TY  - JOUR
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Hilmas, Greg E.
AU  - Fahrenholtz, William G.
AU  - Brenner, Donald W.
AU  - Maria, Jon‐Paul
AU  - Wolfe, Douglas E.
AU  - Zurek, Eva
AU  - Campilongo, Xiomara
AU  - Curtarolo, Stefano
PY  - 2024
UR  - https://dais.sanu.ac.rs/123456789/16517
AB  - Super-hard (Hf,Mo,Ti,V,W)B2 was synthesized by boro-carbothermal reduction and densified by spark plasma sintering. This composition was produced for the first time as a single-phase ceramic in the present research. The optimized ceramic had a single hexagonal AlB2-type crystalline phase with a grain size of 3.8 µm and homogeneous distribution of the constituent metals. The Vickers hardness exhibited the indentation size effect, increasing from 27 GPa at a load of 9.8 N to as high as 66 GPa at a load of 0.49 N. This is the highest hardness reported to date for high entropy boride ceramics.
PB  - Wiley
T2  - Journal of the American Ceramic Society
T1  - A super‐hard high entropy boride containing Hf, Mo, Ti, V, and W
DO  - 10.1111/jace.19795
UR  - https://hdl.handle.net/21.15107/rcub_dais_16517
ER  - 

@article{
author = "Filipović, Suzana and Obradović, Nina and Hilmas, Greg E. and Fahrenholtz, William G. and Brenner, Donald W. and Maria, Jon‐Paul and Wolfe, Douglas E. and Zurek, Eva and Campilongo, Xiomara and Curtarolo, Stefano",
year = "2024",
abstract = "Super-hard (Hf,Mo,Ti,V,W)B2 was synthesized by boro-carbothermal reduction and densified by spark plasma sintering. This composition was produced for the first time as a single-phase ceramic in the present research. The optimized ceramic had a single hexagonal AlB2-type crystalline phase with a grain size of 3.8 µm and homogeneous distribution of the constituent metals. The Vickers hardness exhibited the indentation size effect, increasing from 27 GPa at a load of 9.8 N to as high as 66 GPa at a load of 0.49 N. This is the highest hardness reported to date for high entropy boride ceramics.",
publisher = "Wiley",
journal = "Journal of the American Ceramic Society",
title = "A super‐hard high entropy boride containing Hf, Mo, Ti, V, and W",
doi = "10.1111/jace.19795",
url = "https://hdl.handle.net/21.15107/rcub_dais_16517"
}

Filipović, S., Obradović, N., Hilmas, G. E., Fahrenholtz, W. G., Brenner, D. W., Maria, J., Wolfe, D. E., Zurek, E., Campilongo, X.,& Curtarolo, S.. (2024). A super‐hard high entropy boride containing Hf, Mo, Ti, V, and W. in Journal of the American Ceramic Society
Wiley..
https://doi.org/10.1111/jace.19795
https://hdl.handle.net/21.15107/rcub_dais_16517

Filipović S, Obradović N, Hilmas GE, Fahrenholtz WG, Brenner DW, Maria J, Wolfe DE, Zurek E, Campilongo X, Curtarolo S. A super‐hard high entropy boride containing Hf, Mo, Ti, V, and W. in Journal of the American Ceramic Society. 2024;.
doi:10.1111/jace.19795
https://hdl.handle.net/21.15107/rcub_dais_16517 .

Filipović, Suzana, Obradović, Nina, Hilmas, Greg E., Fahrenholtz, William G., Brenner, Donald W., Maria, Jon‐Paul, Wolfe, Douglas E., Zurek, Eva, Campilongo, Xiomara, Curtarolo, Stefano, "A super‐hard high entropy boride containing Hf, Mo, Ti, V, and W" in Journal of the American Ceramic Society (2024),
https://doi.org/10.1111/jace.19795 .,
https://hdl.handle.net/21.15107/rcub_dais_16517 .

TY  - JOUR
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Corlett, Cole
AU  - Fahrenholtz, William G.
AU  - Rosenschon, Martin
AU  - Füglein, Ekkehard
AU  - Dojčilović, Radovan
AU  - Tošić, Dragana
AU  - Petrović, Jovana
AU  - Đorđević, Antonije
AU  - Vlahović, Branislav
AU  - Pavlović, Vladimir B.
PY  - 2024
UR  - https://dais.sanu.ac.rs/123456789/16516
AB  - Ceramic/polymer composites can be chemically stable, mechanically strong, and flexible, which make them candidates for electric devices, such as pressure or temperature sensors, energy storage or harvesting devices, actuators, and so forth. Depending on the application, various electrical properties are of importance. Polymers usually have low dielectric permittivity, but increased dielectric permittivity can be achieved by the addition of the ceramic fillers with high dielectric constant. With the aim to enhance dielectric properties of the composite without loss of flexibility, 5 wt% of BaTiO3-Fe2O3 powder was added into a polyvinylidene fluoride matrix. The powder was prepared by different synthesis conditions to produce core/shell structures. The effect of the phase composition and morphology of the BaTiO3-Fe2O3 core/shell filler on the structure and lattice dynamics of the polymer composites was investigated. Based on the results of the thermal analysis, various parameters of ceramic/polymer composites were determined. Differences in the phase composition and morphology of the filler have an influence on the formation of various polyvinylidene fluoride allomorphs and the degree of crystallinity. Furthermore, the dielectric performances of pure polyvinylidene fluoride and the polymer/ceramic composites were measured.
PB  - Wiley
T2  - Journal of Applied Polymer Science
T1  - Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite
SP  - e55040
VL  - 141
IS  - 10
DO  - 10.1002/app.55040
UR  - https://hdl.handle.net/21.15107/rcub_dais_16516
ER  - 

@article{
author = "Filipović, Suzana and Obradović, Nina and Corlett, Cole and Fahrenholtz, William G. and Rosenschon, Martin and Füglein, Ekkehard and Dojčilović, Radovan and Tošić, Dragana and Petrović, Jovana and Đorđević, Antonije and Vlahović, Branislav and Pavlović, Vladimir B.",
year = "2024",
abstract = "Ceramic/polymer composites can be chemically stable, mechanically strong, and flexible, which make them candidates for electric devices, such as pressure or temperature sensors, energy storage or harvesting devices, actuators, and so forth. Depending on the application, various electrical properties are of importance. Polymers usually have low dielectric permittivity, but increased dielectric permittivity can be achieved by the addition of the ceramic fillers with high dielectric constant. With the aim to enhance dielectric properties of the composite without loss of flexibility, 5 wt% of BaTiO3-Fe2O3 powder was added into a polyvinylidene fluoride matrix. The powder was prepared by different synthesis conditions to produce core/shell structures. The effect of the phase composition and morphology of the BaTiO3-Fe2O3 core/shell filler on the structure and lattice dynamics of the polymer composites was investigated. Based on the results of the thermal analysis, various parameters of ceramic/polymer composites were determined. Differences in the phase composition and morphology of the filler have an influence on the formation of various polyvinylidene fluoride allomorphs and the degree of crystallinity. Furthermore, the dielectric performances of pure polyvinylidene fluoride and the polymer/ceramic composites were measured.",
publisher = "Wiley",
journal = "Journal of Applied Polymer Science",
title = "Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite",
pages = "e55040",
volume = "141",
number = "10",
doi = "10.1002/app.55040",
url = "https://hdl.handle.net/21.15107/rcub_dais_16516"
}

Filipović, S., Obradović, N., Corlett, C., Fahrenholtz, W. G., Rosenschon, M., Füglein, E., Dojčilović, R., Tošić, D., Petrović, J., Đorđević, A., Vlahović, B.,& Pavlović, V. B.. (2024). Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite. in Journal of Applied Polymer Science
Wiley., 141(10), e55040.
https://doi.org/10.1002/app.55040
https://hdl.handle.net/21.15107/rcub_dais_16516

Filipović S, Obradović N, Corlett C, Fahrenholtz WG, Rosenschon M, Füglein E, Dojčilović R, Tošić D, Petrović J, Đorđević A, Vlahović B, Pavlović VB. Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite. in Journal of Applied Polymer Science. 2024;141(10):e55040.
doi:10.1002/app.55040
https://hdl.handle.net/21.15107/rcub_dais_16516 .

Filipović, Suzana, Obradović, Nina, Corlett, Cole, Fahrenholtz, William G., Rosenschon, Martin, Füglein, Ekkehard, Dojčilović, Radovan, Tošić, Dragana, Petrović, Jovana, Đorđević, Antonije, Vlahović, Branislav, Pavlović, Vladimir B., "Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite" in Journal of Applied Polymer Science, 141, no. 10 (2024):e55040,
https://doi.org/10.1002/app.55040 .,
https://hdl.handle.net/21.15107/rcub_dais_16516 .

TY  - JOUR
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Corlett, Cole
AU  - Fahrenholtz, William G.
AU  - Rosenschon, Martin
AU  - Füglein, Ekkehard
AU  - Dojčilović, Radovan
AU  - Tošić, Dragana
AU  - Petrović, Jovana
AU  - Đorđević, Antonije
AU  - Vlahović, Branislav
AU  - Pavlović, Vladimir B.
PY  - 2024
UR  - https://dais.sanu.ac.rs/123456789/16243
AB  - Ceramic/polymer composites can be chemically stable, mechanically strong, and flexible, which make them candidates for electric devices, such as pressure or temperature sensors, energy storage or harvesting devices, actuators, and so forth. Depending on the application, various electrical properties are of importance. Polymers usually have low dielectric permittivity, but increased dielectric permittivity can be achieved by the addition of the ceramic fillers with high dielectric constant. With the aim to enhance dielectric properties of the composite without loss of flexibility, 5 wt% of BaTiO3-Fe2O3 powder was added into a polyvinylidene fluoride matrix. The powder was prepared by different synthesis conditions to produce core/shell structures. The effect of the phase composition and morphology of the BaTiO3-Fe2O3 core/shell filler on the structure and lattice dynamics of the polymer composites was investigated. Based on the results of the thermal analysis, various parameters of ceramic/polymer composites were determined. Differences in the phase composition and morphology of the filler have an influence on the formation of various polyvinylidene fluoride allomorphs and the degree of crystallinity. Furthermore, the dielectric performances of pure polyvinylidene fluoride and the polymer/ceramic composites were measured.
PB  - Wiley
T2  - Journal of Applied Polymer Science
T1  - Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite
SP  - e55040
VL  - 141
IS  - 10
DO  - 10.1002/app.55040
UR  - https://hdl.handle.net/21.15107/rcub_dais_16516
ER  - 

@article{
author = "Filipović, Suzana and Obradović, Nina and Corlett, Cole and Fahrenholtz, William G. and Rosenschon, Martin and Füglein, Ekkehard and Dojčilović, Radovan and Tošić, Dragana and Petrović, Jovana and Đorđević, Antonije and Vlahović, Branislav and Pavlović, Vladimir B.",
year = "2024",
abstract = "Ceramic/polymer composites can be chemically stable, mechanically strong, and flexible, which make them candidates for electric devices, such as pressure or temperature sensors, energy storage or harvesting devices, actuators, and so forth. Depending on the application, various electrical properties are of importance. Polymers usually have low dielectric permittivity, but increased dielectric permittivity can be achieved by the addition of the ceramic fillers with high dielectric constant. With the aim to enhance dielectric properties of the composite without loss of flexibility, 5 wt% of BaTiO3-Fe2O3 powder was added into a polyvinylidene fluoride matrix. The powder was prepared by different synthesis conditions to produce core/shell structures. The effect of the phase composition and morphology of the BaTiO3-Fe2O3 core/shell filler on the structure and lattice dynamics of the polymer composites was investigated. Based on the results of the thermal analysis, various parameters of ceramic/polymer composites were determined. Differences in the phase composition and morphology of the filler have an influence on the formation of various polyvinylidene fluoride allomorphs and the degree of crystallinity. Furthermore, the dielectric performances of pure polyvinylidene fluoride and the polymer/ceramic composites were measured.",
publisher = "Wiley",
journal = "Journal of Applied Polymer Science",
title = "Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite",
pages = "e55040",
volume = "141",
number = "10",
doi = "10.1002/app.55040",
url = "https://hdl.handle.net/21.15107/rcub_dais_16516"
}

Filipović, S., Obradović, N., Corlett, C., Fahrenholtz, W. G., Rosenschon, M., Füglein, E., Dojčilović, R., Tošić, D., Petrović, J., Đorđević, A., Vlahović, B.,& Pavlović, V. B.. (2024). Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite. in Journal of Applied Polymer Science
Wiley., 141(10), e55040.
https://doi.org/10.1002/app.55040
https://hdl.handle.net/21.15107/rcub_dais_16516

Filipović S, Obradović N, Corlett C, Fahrenholtz WG, Rosenschon M, Füglein E, Dojčilović R, Tošić D, Petrović J, Đorđević A, Vlahović B, Pavlović VB. Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite. in Journal of Applied Polymer Science. 2024;141(10):e55040.
doi:10.1002/app.55040
https://hdl.handle.net/21.15107/rcub_dais_16516 .

Filipović, Suzana, Obradović, Nina, Corlett, Cole, Fahrenholtz, William G., Rosenschon, Martin, Füglein, Ekkehard, Dojčilović, Radovan, Tošić, Dragana, Petrović, Jovana, Đorđević, Antonije, Vlahović, Branislav, Pavlović, Vladimir B., "Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite" in Journal of Applied Polymer Science, 141, no. 10 (2024):e55040,
https://doi.org/10.1002/app.55040 .,
https://hdl.handle.net/21.15107/rcub_dais_16516 .

TY  - CONF
AU  - Filipović, Suzana
AU  - Hilmas, Gregory E.
AU  - Fahrenholtz, William G.
AU  - Obradović, Nina
AU  - Curtarolo, Stefano
PY  - 2024
UR  - https://dais.sanu.ac.rs/123456789/16386
AB  - Dual phase high entropy ceramics are attractive due to potential synergetic effects of the constituents on mechanical properties and thermal stability. In this research, dense, dual phase (Hf,Mo,Ti,W,Z) B2-(Hf.Mo.Ti.W,Zr)C powder was synthesized by varying the contents of the transition metals in the final product. The co-synthesis method was used to obtain boride and carbide constituents by boro/ carbothermal reduction of mixtures of oxides and appropriate amounts of carbon black and B4C. Solid solution formation and densification of the reacted powders were done utilizing two step spark plasma sintering or hot pressing processes. Phase compositions of the produced ceramics were identified by x-ray diffraction while chemical compositions were measured using energy dispersive spectroscopy. The final microstructures showed submicron grains due to pining effect of the two phases. Investigation of the mechanical properties showed increasing in Vickers hardness values s up to 48.6 2.2 GPa for applied load of 0.49N for compositions with optimized elemental contents. Room temperature strength was also measured.
PB  - American Ceramic Society
C3  - Abstract Book / 48th International Conference & Exposition on Advanced Ceramics and Composites, January 28–February 2, 2024, Daytona Beach, Florida
T1  - Synthesis and Properties of (Hf,Mo,Ti,W,Zr)B2-(Hf,Mo,Ti,W,Z)C Dual Phase Ceramics
UR  - https://hdl.handle.net/21.15107/rcub_dais_16386
ER  - 

@conference{
author = "Filipović, Suzana and Hilmas, Gregory E. and Fahrenholtz, William G. and Obradović, Nina and Curtarolo, Stefano",
year = "2024",
abstract = "Dual phase high entropy ceramics are attractive due to potential synergetic effects of the constituents on mechanical properties and thermal stability. In this research, dense, dual phase (Hf,Mo,Ti,W,Z) B2-(Hf.Mo.Ti.W,Zr)C powder was synthesized by varying the contents of the transition metals in the final product. The co-synthesis method was used to obtain boride and carbide constituents by boro/ carbothermal reduction of mixtures of oxides and appropriate amounts of carbon black and B4C. Solid solution formation and densification of the reacted powders were done utilizing two step spark plasma sintering or hot pressing processes. Phase compositions of the produced ceramics were identified by x-ray diffraction while chemical compositions were measured using energy dispersive spectroscopy. The final microstructures showed submicron grains due to pining effect of the two phases. Investigation of the mechanical properties showed increasing in Vickers hardness values s up to 48.6 2.2 GPa for applied load of 0.49N for compositions with optimized elemental contents. Room temperature strength was also measured.",
publisher = "American Ceramic Society",
journal = "Abstract Book / 48th International Conference & Exposition on Advanced Ceramics and Composites, January 28–February 2, 2024, Daytona Beach, Florida",
title = "Synthesis and Properties of (Hf,Mo,Ti,W,Zr)B2-(Hf,Mo,Ti,W,Z)C Dual Phase Ceramics",
url = "https://hdl.handle.net/21.15107/rcub_dais_16386"
}

Filipović, S., Hilmas, G. E., Fahrenholtz, W. G., Obradović, N.,& Curtarolo, S.. (2024). Synthesis and Properties of (Hf,Mo,Ti,W,Zr)B2-(Hf,Mo,Ti,W,Z)C Dual Phase Ceramics. in Abstract Book / 48th International Conference & Exposition on Advanced Ceramics and Composites, January 28–February 2, 2024, Daytona Beach, Florida
American Ceramic Society..
https://hdl.handle.net/21.15107/rcub_dais_16386

Filipović S, Hilmas GE, Fahrenholtz WG, Obradović N, Curtarolo S. Synthesis and Properties of (Hf,Mo,Ti,W,Zr)B2-(Hf,Mo,Ti,W,Z)C Dual Phase Ceramics. in Abstract Book / 48th International Conference & Exposition on Advanced Ceramics and Composites, January 28–February 2, 2024, Daytona Beach, Florida. 2024;.
https://hdl.handle.net/21.15107/rcub_dais_16386 .

Filipović, Suzana, Hilmas, Gregory E., Fahrenholtz, William G., Obradović, Nina, Curtarolo, Stefano, "Synthesis and Properties of (Hf,Mo,Ti,W,Zr)B2-(Hf,Mo,Ti,W,Z)C Dual Phase Ceramics" in Abstract Book / 48th International Conference & Exposition on Advanced Ceramics and Composites, January 28–February 2, 2024, Daytona Beach, Florida (2024),
https://hdl.handle.net/21.15107/rcub_dais_16386 .

TY  - CONF
AU  - Swanson, R.
AU  - Kosanović, Darko
AU  - Chapman, M.
AU  - Uchic, M. D.
AU  - Fahrenholtz, William G.
AU  - McCormack, S. J.
PY  - 2024
UR  - https://dais.sanu.ac.rs/123456789/16382
AB  - Standard ultra-high temperature ceramic (UHTC) manufacturing results in components with large differences in properties due to variability in microstructural “critical flaw” distributions. Critical flaws can be any irregularity in a component, such as a secondary phase, cracks, pores, etc. This is problematic when designing reproducible UHTC components. The goal of this project is to understand how these critical flaws evolve during hot pressing of ZrB2 (a UHTC) by examining them in 3D. This study incorporates 3D imaging such as (i) preliminary in-situ high-temperature pressureless sintering X-ray µ-CT, (ii) ex-situ X-ray µ-CT, and (iii) 3D electron imaging and backscattered diffraction data collected at different stages of densification. 3D microstructure statistics along with unique observations of individual pore and secondary phase evolution will be presented. This data is brought together to give a holistic view of the densification of ZrB2 during hot pressing at multiple length scales. This data will be incorporated into a process-structure-property (PSP) database for statistical modeling to reduce uncertainty during ZrB2 processing.
PB  - American Ceramic Society
C3  - Abstract Book / 48th International Conference & Exposition on Advanced Ceramics and Composites, January 28–February 2, 2024, Daytona Beach, Florida
T1  - High-fidelity 3D microstructural characterization of ZrB2 during hot-pressing (Invited)
UR  - https://hdl.handle.net/21.15107/rcub_dais_16382
ER  - 

@conference{
author = "Swanson, R. and Kosanović, Darko and Chapman, M. and Uchic, M. D. and Fahrenholtz, William G. and McCormack, S. J.",
year = "2024",
abstract = "Standard ultra-high temperature ceramic (UHTC) manufacturing results in components with large differences in properties due to variability in microstructural “critical flaw” distributions. Critical flaws can be any irregularity in a component, such as a secondary phase, cracks, pores, etc. This is problematic when designing reproducible UHTC components. The goal of this project is to understand how these critical flaws evolve during hot pressing of ZrB2 (a UHTC) by examining them in 3D. This study incorporates 3D imaging such as (i) preliminary in-situ high-temperature pressureless sintering X-ray µ-CT, (ii) ex-situ X-ray µ-CT, and (iii) 3D electron imaging and backscattered diffraction data collected at different stages of densification. 3D microstructure statistics along with unique observations of individual pore and secondary phase evolution will be presented. This data is brought together to give a holistic view of the densification of ZrB2 during hot pressing at multiple length scales. This data will be incorporated into a process-structure-property (PSP) database for statistical modeling to reduce uncertainty during ZrB2 processing.",
publisher = "American Ceramic Society",
journal = "Abstract Book / 48th International Conference & Exposition on Advanced Ceramics and Composites, January 28–February 2, 2024, Daytona Beach, Florida",
title = "High-fidelity 3D microstructural characterization of ZrB2 during hot-pressing (Invited)",
url = "https://hdl.handle.net/21.15107/rcub_dais_16382"
}

Swanson, R., Kosanović, D., Chapman, M., Uchic, M. D., Fahrenholtz, W. G.,& McCormack, S. J.. (2024). High-fidelity 3D microstructural characterization of ZrB2 during hot-pressing (Invited). in Abstract Book / 48th International Conference & Exposition on Advanced Ceramics and Composites, January 28–February 2, 2024, Daytona Beach, Florida
American Ceramic Society..
https://hdl.handle.net/21.15107/rcub_dais_16382

Swanson R, Kosanović D, Chapman M, Uchic MD, Fahrenholtz WG, McCormack SJ. High-fidelity 3D microstructural characterization of ZrB2 during hot-pressing (Invited). in Abstract Book / 48th International Conference & Exposition on Advanced Ceramics and Composites, January 28–February 2, 2024, Daytona Beach, Florida. 2024;.
https://hdl.handle.net/21.15107/rcub_dais_16382 .

Swanson, R., Kosanović, Darko, Chapman, M., Uchic, M. D., Fahrenholtz, William G., McCormack, S. J., "High-fidelity 3D microstructural characterization of ZrB2 during hot-pressing (Invited)" in Abstract Book / 48th International Conference & Exposition on Advanced Ceramics and Composites, January 28–February 2, 2024, Daytona Beach, Florida (2024),
https://hdl.handle.net/21.15107/rcub_dais_16382 .

TY  - JOUR
AU  - Divilov, Simon
AU  - Eckert, Hagen
AU  - Hicks, David
AU  - Oses, Corey
AU  - Toher, Cormac
AU  - Friedrich, Rico
AU  - Esters, Marco
AU  - Mehl, Michael J.
AU  - Zettel, Adam C.
AU  - Lederer, Yoav
AU  - Zurek, Eva
AU  - Maria, Jon-Paul
AU  - Brenner, Donald W.
AU  - Campilongo, Xiomara
AU  - Filipović, Suzana
AU  - Fahrenholtz, William G.
AU  - Ryan, Caillin J.
AU  - DeSalle, Christopher M.
AU  - Crealese, Ryan J.
AU  - Wolfe, Douglas E.
AU  - Calzolari, Arrigo
AU  - Curtarolo, Stefano
PY  - 2024
UR  - https://dais.sanu.ac.rs/123456789/16242
AB  - The need for improved functionalities in extreme environments is fuelling interest in high-entropy ceramics1,2,3. Except for the computational discovery of high-entropy carbides, performed with the entropy-forming-ability descriptor4, most innovation has been slowly driven by experimental means1,2,3. Hence, advancement in the field needs more theoretical contributions. Here we introduce disordered enthalpy–entropy descriptor (DEED), a descriptor that captures the balance between entropy gains and enthalpy costs, allowing the correct classification of functional synthesizability of multicomponent ceramics, regardless of chemistry and structure. To make our calculations possible, we have developed a convolutional algorithm that drastically reduces computational resources. Moreover, DEED guides the experimental discovery of new single-phase high-entropy carbonitrides and borides. This work, integrated into the AFLOW computational ecosystem, provides an array of potential new candidates, ripe for experimental discoveries.
PB  - Springer Science and Business Media LLC
T2  - Nature
T1  - Disordered enthalpy–entropy descriptor for high-entropy ceramics discovery
SP  - 66
EP  - 73
VL  - 625
IS  - 7993
DO  - 10.1038/s41586-023-06786-y
UR  - https://hdl.handle.net/21.15107/rcub_dais_16242
ER  - 

@article{
author = "Divilov, Simon and Eckert, Hagen and Hicks, David and Oses, Corey and Toher, Cormac and Friedrich, Rico and Esters, Marco and Mehl, Michael J. and Zettel, Adam C. and Lederer, Yoav and Zurek, Eva and Maria, Jon-Paul and Brenner, Donald W. and Campilongo, Xiomara and Filipović, Suzana and Fahrenholtz, William G. and Ryan, Caillin J. and DeSalle, Christopher M. and Crealese, Ryan J. and Wolfe, Douglas E. and Calzolari, Arrigo and Curtarolo, Stefano",
year = "2024",
abstract = "The need for improved functionalities in extreme environments is fuelling interest in high-entropy ceramics1,2,3. Except for the computational discovery of high-entropy carbides, performed with the entropy-forming-ability descriptor4, most innovation has been slowly driven by experimental means1,2,3. Hence, advancement in the field needs more theoretical contributions. Here we introduce disordered enthalpy–entropy descriptor (DEED), a descriptor that captures the balance between entropy gains and enthalpy costs, allowing the correct classification of functional synthesizability of multicomponent ceramics, regardless of chemistry and structure. To make our calculations possible, we have developed a convolutional algorithm that drastically reduces computational resources. Moreover, DEED guides the experimental discovery of new single-phase high-entropy carbonitrides and borides. This work, integrated into the AFLOW computational ecosystem, provides an array of potential new candidates, ripe for experimental discoveries.",
publisher = "Springer Science and Business Media LLC",
journal = "Nature",
title = "Disordered enthalpy–entropy descriptor for high-entropy ceramics discovery",
pages = "66-73",
volume = "625",
number = "7993",
doi = "10.1038/s41586-023-06786-y",
url = "https://hdl.handle.net/21.15107/rcub_dais_16242"
}

Divilov, S., Eckert, H., Hicks, D., Oses, C., Toher, C., Friedrich, R., Esters, M., Mehl, M. J., Zettel, A. C., Lederer, Y., Zurek, E., Maria, J., Brenner, D. W., Campilongo, X., Filipović, S., Fahrenholtz, W. G., Ryan, C. J., DeSalle, C. M., Crealese, R. J., Wolfe, D. E., Calzolari, A.,& Curtarolo, S.. (2024). Disordered enthalpy–entropy descriptor for high-entropy ceramics discovery. in Nature
Springer Science and Business Media LLC., 625(7993), 66-73.
https://doi.org/10.1038/s41586-023-06786-y
https://hdl.handle.net/21.15107/rcub_dais_16242

Divilov S, Eckert H, Hicks D, Oses C, Toher C, Friedrich R, Esters M, Mehl MJ, Zettel AC, Lederer Y, Zurek E, Maria J, Brenner DW, Campilongo X, Filipović S, Fahrenholtz WG, Ryan CJ, DeSalle CM, Crealese RJ, Wolfe DE, Calzolari A, Curtarolo S. Disordered enthalpy–entropy descriptor for high-entropy ceramics discovery. in Nature. 2024;625(7993):66-73.
doi:10.1038/s41586-023-06786-y
https://hdl.handle.net/21.15107/rcub_dais_16242 .

Divilov, Simon, Eckert, Hagen, Hicks, David, Oses, Corey, Toher, Cormac, Friedrich, Rico, Esters, Marco, Mehl, Michael J., Zettel, Adam C., Lederer, Yoav, Zurek, Eva, Maria, Jon-Paul, Brenner, Donald W., Campilongo, Xiomara, Filipović, Suzana, Fahrenholtz, William G., Ryan, Caillin J., DeSalle, Christopher M., Crealese, Ryan J., Wolfe, Douglas E., Calzolari, Arrigo, Curtarolo, Stefano, "Disordered enthalpy–entropy descriptor for high-entropy ceramics discovery" in Nature, 625, no. 7993 (2024):66-73,
https://doi.org/10.1038/s41586-023-06786-y .,
https://hdl.handle.net/21.15107/rcub_dais_16242 .

TY  - JOUR
AU  - Corlett, Cole A.
AU  - Obradović, Nina
AU  - Watts, Jeremy L.
AU  - Bohannan, Eric W.
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/14708
AB  - The synthesis, densification behavior, and crystallographic site occupancy were investigated for four different spinel-based ceramics, including a high-entropy spinel (Co0.2Cu0.2Mg0.2Ni0.2 Zn0.2)Al2O4. Each composition was reacted to form a single phase, but analysis of X-ray diffraction patterns revealed differences in cation site occupancy with the high-entropy spinel being nearly fully normal. Densification behavior was investigated and showed that fully dense ceramics could be produced by hot pressing at temperatures as low as 1375°C for all compositions. Vickers’ hardness values were at least 10 GPa for all compositions. The cations present in the high-entropy spinel appear to have a stabilizing effect that led to nearly normal site occupancy compared to full cation inversion behavior of nickel aluminate spinel. This is the first report that compares cation site occupancy of a high-entropy spinel to conventional spinel ceramics.
PB  - Informa UK Limited
T2  - Journal of Asian Ceramic Societies
T1  - Synthesis, densification, and cation inversion in high entropy (Co,Cu,Mg,Ni,Zn)Al2O4 spinel
SP  - 1
SP  - 330
EP  - 8
EP  - 337
VL  - 11
IS  - 3
DO  - 10.1080/21870764.2023.2227535
UR  - https://hdl.handle.net/21.15107/rcub_dais_14708
ER  - 

@article{
author = "Corlett, Cole A. and Obradović, Nina and Watts, Jeremy L. and Bohannan, Eric W. and Fahrenholtz, William G.",
year = "2023",
abstract = "The synthesis, densification behavior, and crystallographic site occupancy were investigated for four different spinel-based ceramics, including a high-entropy spinel (Co0.2Cu0.2Mg0.2Ni0.2 Zn0.2)Al2O4. Each composition was reacted to form a single phase, but analysis of X-ray diffraction patterns revealed differences in cation site occupancy with the high-entropy spinel being nearly fully normal. Densification behavior was investigated and showed that fully dense ceramics could be produced by hot pressing at temperatures as low as 1375°C for all compositions. Vickers’ hardness values were at least 10 GPa for all compositions. The cations present in the high-entropy spinel appear to have a stabilizing effect that led to nearly normal site occupancy compared to full cation inversion behavior of nickel aluminate spinel. This is the first report that compares cation site occupancy of a high-entropy spinel to conventional spinel ceramics.",
publisher = "Informa UK Limited",
journal = "Journal of Asian Ceramic Societies",
title = "Synthesis, densification, and cation inversion in high entropy (Co,Cu,Mg,Ni,Zn)Al2O4 spinel",
pages = "1-330-8-337",
volume = "11",
number = "3",
doi = "10.1080/21870764.2023.2227535",
url = "https://hdl.handle.net/21.15107/rcub_dais_14708"
}

Corlett, C. A., Obradović, N., Watts, J. L., Bohannan, E. W.,& Fahrenholtz, W. G.. (2023). Synthesis, densification, and cation inversion in high entropy (Co,Cu,Mg,Ni,Zn)Al2O4 spinel. in Journal of Asian Ceramic Societies
Informa UK Limited., 11(3), 1-8.
https://doi.org/10.1080/21870764.2023.2227535
https://hdl.handle.net/21.15107/rcub_dais_14708

Corlett CA, Obradović N, Watts JL, Bohannan EW, Fahrenholtz WG. Synthesis, densification, and cation inversion in high entropy (Co,Cu,Mg,Ni,Zn)Al2O4 spinel. in Journal of Asian Ceramic Societies. 2023;11(3):1-8.
doi:10.1080/21870764.2023.2227535
https://hdl.handle.net/21.15107/rcub_dais_14708 .

Corlett, Cole A., Obradović, Nina, Watts, Jeremy L., Bohannan, Eric W., Fahrenholtz, William G., "Synthesis, densification, and cation inversion in high entropy (Co,Cu,Mg,Ni,Zn)Al2O4 spinel" in Journal of Asian Ceramic Societies, 11, no. 3 (2023):1-8,
https://doi.org/10.1080/21870764.2023.2227535 .,
https://hdl.handle.net/21.15107/rcub_dais_14708 .

TY  - JOUR
AU  - Obradović, Nina
AU  - Feng, Lun
AU  - Filipović, Suzana
AU  - Mirković, Miljana
AU  - Kosanović, Darko
AU  - Rogan, Jelena
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/14877
AB  - Zirconium carbide ceramics were prepared by carbothermal reduction of ZrO2 and C that were mixed by high-energy ball milling. Powders were milled for times from 0 to 120 min in air. As milling time increased, the surface area of the powders increased, indicating significant particle size reduction. Milled powders were reacted at 1600 °C and then densified by spark plasma sintering at 2000 °C, which was sufficient to convert the starting powders to zirconium carbide. Unmilled powders did not reach full density. Milled powders reached full density, but ZrO2 impurities were found for specimens prepared from powders milled for 60 and 120 min. Microstructure analysis showed that grain size was less than 2 µm for ceramics produced from powder milled for 15 min. Based on densification onset temperature and impurity levels, a milling time of 15 min gives the best balance of particle size reduction to promote densification while minimizing impurity levels.
PB  - Elsevier BV
T2  - Journal of the European Ceramic Society
T1  - Effect of mechanical activation on carbothermal synthesis and densification of ZrC
SP  - 7306
EP  - 7313
VL  - 43
DO  - 10.1016/j.jeurceramsoc.2023.08.007
UR  - https://hdl.handle.net/21.15107/rcub_dais_14877
ER  - 

@article{
author = "Obradović, Nina and Feng, Lun and Filipović, Suzana and Mirković, Miljana and Kosanović, Darko and Rogan, Jelena and Fahrenholtz, William G.",
year = "2023",
abstract = "Zirconium carbide ceramics were prepared by carbothermal reduction of ZrO2 and C that were mixed by high-energy ball milling. Powders were milled for times from 0 to 120 min in air. As milling time increased, the surface area of the powders increased, indicating significant particle size reduction. Milled powders were reacted at 1600 °C and then densified by spark plasma sintering at 2000 °C, which was sufficient to convert the starting powders to zirconium carbide. Unmilled powders did not reach full density. Milled powders reached full density, but ZrO2 impurities were found for specimens prepared from powders milled for 60 and 120 min. Microstructure analysis showed that grain size was less than 2 µm for ceramics produced from powder milled for 15 min. Based on densification onset temperature and impurity levels, a milling time of 15 min gives the best balance of particle size reduction to promote densification while minimizing impurity levels.",
publisher = "Elsevier BV",
journal = "Journal of the European Ceramic Society",
title = "Effect of mechanical activation on carbothermal synthesis and densification of ZrC",
pages = "7306-7313",
volume = "43",
doi = "10.1016/j.jeurceramsoc.2023.08.007",
url = "https://hdl.handle.net/21.15107/rcub_dais_14877"
}

Obradović, N., Feng, L., Filipović, S., Mirković, M., Kosanović, D., Rogan, J.,& Fahrenholtz, W. G.. (2023). Effect of mechanical activation on carbothermal synthesis and densification of ZrC. in Journal of the European Ceramic Society
Elsevier BV., 43, 7306-7313.
https://doi.org/10.1016/j.jeurceramsoc.2023.08.007
https://hdl.handle.net/21.15107/rcub_dais_14877

Obradović N, Feng L, Filipović S, Mirković M, Kosanović D, Rogan J, Fahrenholtz WG. Effect of mechanical activation on carbothermal synthesis and densification of ZrC. in Journal of the European Ceramic Society. 2023;43:7306-7313.
doi:10.1016/j.jeurceramsoc.2023.08.007
https://hdl.handle.net/21.15107/rcub_dais_14877 .

Obradović, Nina, Feng, Lun, Filipović, Suzana, Mirković, Miljana, Kosanović, Darko, Rogan, Jelena, Fahrenholtz, William G., "Effect of mechanical activation on carbothermal synthesis and densification of ZrC" in Journal of the European Ceramic Society, 43 (2023):7306-7313,
https://doi.org/10.1016/j.jeurceramsoc.2023.08.007 .,
https://hdl.handle.net/21.15107/rcub_dais_14877 .

TY  - JOUR
AU  - Stanfield, Austin D.
AU  - Smith, Steven M.
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Buljak, Vladimir
AU  - Hilmas, Gregory E.
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/15143
AB  - Final-stage sintering was analyzed for nominally phase pure zirconium diboride synthesized by borothermal reduction of high-purity ZrO2. Analysis was conducted on ZrB2 ceramics with relative densities greater than 90% using the Nabarro–Herring stress–directed vacancy diffusion model. Temperatures of 1900°C or above and an applied uniaxial pressure of 50 MPa were required to fully densify ZrB2 ceramics by direct current sintering. Ram travel data were collected and used to determine the relative density of the specimens during sintering. Specimens sintered between 1900 and 2100°C achieved relative densities greater than 97%, whereas specimens sintered below 1900°C failed to reach the final stage of sintering. The average grain size ranged from 1.0 to 14.7 μm. The activation energy was calculated from the slope of an Arrhenius plot that used the Kalish equation. The activation energy was 162 ± 34 kJ/mol, which is consistent with the activation energy for dislocation movement in ZrB2. The diffusion coefficients for dislocation motion that controls densification were 5.1 × 10−6 cm2/s at 1900°C and 5.1 × 10−5 cm2/s at 2100°C, as calculated from activation energy and average grain sizes. This study provides evidence that the dominant mechanism for final-stage sintering of ZrB2 ceramics is dislocation motion.
PB  - Wiley
T2  - Journal of the American Ceramic Society
T1  - Final‐stage densification kinetics of direct current–sintered ZrB2
SP  - 5654
EP  - 5661
VL  - 106
IS  - 10
DO  - 10.1111/jace.19212
UR  - https://hdl.handle.net/21.15107/rcub_dais_15143
ER  - 

@article{
author = "Stanfield, Austin D. and Smith, Steven M. and Filipović, Suzana and Obradović, Nina and Buljak, Vladimir and Hilmas, Gregory E. and Fahrenholtz, William G.",
year = "2023",
abstract = "Final-stage sintering was analyzed for nominally phase pure zirconium diboride synthesized by borothermal reduction of high-purity ZrO2. Analysis was conducted on ZrB2 ceramics with relative densities greater than 90% using the Nabarro–Herring stress–directed vacancy diffusion model. Temperatures of 1900°C or above and an applied uniaxial pressure of 50 MPa were required to fully densify ZrB2 ceramics by direct current sintering. Ram travel data were collected and used to determine the relative density of the specimens during sintering. Specimens sintered between 1900 and 2100°C achieved relative densities greater than 97%, whereas specimens sintered below 1900°C failed to reach the final stage of sintering. The average grain size ranged from 1.0 to 14.7 μm. The activation energy was calculated from the slope of an Arrhenius plot that used the Kalish equation. The activation energy was 162 ± 34 kJ/mol, which is consistent with the activation energy for dislocation movement in ZrB2. The diffusion coefficients for dislocation motion that controls densification were 5.1 × 10−6 cm2/s at 1900°C and 5.1 × 10−5 cm2/s at 2100°C, as calculated from activation energy and average grain sizes. This study provides evidence that the dominant mechanism for final-stage sintering of ZrB2 ceramics is dislocation motion.",
publisher = "Wiley",
journal = "Journal of the American Ceramic Society",
title = "Final‐stage densification kinetics of direct current–sintered ZrB2",
pages = "5654-5661",
volume = "106",
number = "10",
doi = "10.1111/jace.19212",
url = "https://hdl.handle.net/21.15107/rcub_dais_15143"
}

Stanfield, A. D., Smith, S. M., Filipović, S., Obradović, N., Buljak, V., Hilmas, G. E.,& Fahrenholtz, W. G.. (2023). Final‐stage densification kinetics of direct current–sintered ZrB2. in Journal of the American Ceramic Society
Wiley., 106(10), 5654-5661.
https://doi.org/10.1111/jace.19212
https://hdl.handle.net/21.15107/rcub_dais_15143

Stanfield AD, Smith SM, Filipović S, Obradović N, Buljak V, Hilmas GE, Fahrenholtz WG. Final‐stage densification kinetics of direct current–sintered ZrB2. in Journal of the American Ceramic Society. 2023;106(10):5654-5661.
doi:10.1111/jace.19212
https://hdl.handle.net/21.15107/rcub_dais_15143 .

Stanfield, Austin D., Smith, Steven M., Filipović, Suzana, Obradović, Nina, Buljak, Vladimir, Hilmas, Gregory E., Fahrenholtz, William G., "Final‐stage densification kinetics of direct current–sintered ZrB2" in Journal of the American Ceramic Society, 106, no. 10 (2023):5654-5661,
https://doi.org/10.1111/jace.19212 .,
https://hdl.handle.net/21.15107/rcub_dais_15143 .

TY  - JOUR
AU  - Stanfield, Austin D.
AU  - Smith, Steven M.
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Buljak, Vladimir
AU  - Hilmas, Gregory E.
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/15196
AB  - Final-stage sintering was analyzed for nominally phase pure zirconium diboride synthesized by borothermal reduction of high-purity ZrO2. Analysis was conducted on ZrB2 ceramics with relative densities greater than 90% using the Nabarro–Herring stress–directed vacancy diffusion model. Temperatures of 1900°C or above and an applied uniaxial pressure of 50 MPa were required to fully densify ZrB2 ceramics by direct current sintering. Ram travel data were collected and used to determine the relative density of the specimens during sintering. Specimens sintered between 1900 and 2100°C achieved relative densities greater than 97%, whereas specimens sintered below 1900°C failed to reach the final stage of sintering. The average grain size ranged from 1.0 to 14.7 μm. The activation energy was calculated from the slope of an Arrhenius plot that used the Kalish equation. The activation energy was 162 ± 34 kJ/mol, which is consistent with the activation energy for dislocation movement in ZrB2. The diffusion coefficients for dislocation motion that controls densification were 5.1 × 10−6 cm2/s at 1900°C and 5.1 × 10−5 cm2/s at 2100°C, as calculated from activation energy and average grain sizes. This study provides evidence that the dominant mechanism for final-stage sintering of ZrB2 ceramics is dislocation motion.
PB  - Wiley
T2  - Journal of the American Ceramic Society
T1  - Final‐stage densification kinetics of direct current–sintered ZrB2
SP  - 5654
EP  - 5661
VL  - 106
IS  - 10
DO  - 10.1111/jace.19212
UR  - https://hdl.handle.net/21.15107/rcub_dais_15196
ER  - 

@article{
author = "Stanfield, Austin D. and Smith, Steven M. and Filipović, Suzana and Obradović, Nina and Buljak, Vladimir and Hilmas, Gregory E. and Fahrenholtz, William G.",
year = "2023",
abstract = "Final-stage sintering was analyzed for nominally phase pure zirconium diboride synthesized by borothermal reduction of high-purity ZrO2. Analysis was conducted on ZrB2 ceramics with relative densities greater than 90% using the Nabarro–Herring stress–directed vacancy diffusion model. Temperatures of 1900°C or above and an applied uniaxial pressure of 50 MPa were required to fully densify ZrB2 ceramics by direct current sintering. Ram travel data were collected and used to determine the relative density of the specimens during sintering. Specimens sintered between 1900 and 2100°C achieved relative densities greater than 97%, whereas specimens sintered below 1900°C failed to reach the final stage of sintering. The average grain size ranged from 1.0 to 14.7 μm. The activation energy was calculated from the slope of an Arrhenius plot that used the Kalish equation. The activation energy was 162 ± 34 kJ/mol, which is consistent with the activation energy for dislocation movement in ZrB2. The diffusion coefficients for dislocation motion that controls densification were 5.1 × 10−6 cm2/s at 1900°C and 5.1 × 10−5 cm2/s at 2100°C, as calculated from activation energy and average grain sizes. This study provides evidence that the dominant mechanism for final-stage sintering of ZrB2 ceramics is dislocation motion.",
publisher = "Wiley",
journal = "Journal of the American Ceramic Society",
title = "Final‐stage densification kinetics of direct current–sintered ZrB2",
pages = "5654-5661",
volume = "106",
number = "10",
doi = "10.1111/jace.19212",
url = "https://hdl.handle.net/21.15107/rcub_dais_15196"
}

Stanfield, A. D., Smith, S. M., Filipović, S., Obradović, N., Buljak, V., Hilmas, G. E.,& Fahrenholtz, W. G.. (2023). Final‐stage densification kinetics of direct current–sintered ZrB2. in Journal of the American Ceramic Society
Wiley., 106(10), 5654-5661.
https://doi.org/10.1111/jace.19212
https://hdl.handle.net/21.15107/rcub_dais_15196

Stanfield AD, Smith SM, Filipović S, Obradović N, Buljak V, Hilmas GE, Fahrenholtz WG. Final‐stage densification kinetics of direct current–sintered ZrB2. in Journal of the American Ceramic Society. 2023;106(10):5654-5661.
doi:10.1111/jace.19212
https://hdl.handle.net/21.15107/rcub_dais_15196 .

Stanfield, Austin D., Smith, Steven M., Filipović, Suzana, Obradović, Nina, Buljak, Vladimir, Hilmas, Gregory E., Fahrenholtz, William G., "Final‐stage densification kinetics of direct current–sintered ZrB2" in Journal of the American Ceramic Society, 106, no. 10 (2023):5654-5661,
https://doi.org/10.1111/jace.19212 .,
https://hdl.handle.net/21.15107/rcub_dais_15196 .

TY  - CONF
AU  - Obradović, Nina
AU  - Filipović, Suzana
AU  - Feng, Lun
AU  - Mirković, M.
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/16181
AB  - Mixtures of ZrO2 and C were prepared by high-energy ball milling. Powders were milled for times from 0 to 120 minutes in air atmosphere. As milling time increased, surface area of powders increased, indicating significant particle size reduction. Milled powders were densified by spark plasma sintering at 2000 °C. Unmilled powders did not reach full density. Milled powders reached full density, but ZrO2 impurities were found for specimens prepared from powders milled for 60 and 120 minutes. Microstructure analysis showed that grain size was less than 2 microns for powder milled for 15 minutes. Based on densification data and impurities level, milling time of
15 minutes appears to give the best balance of particle size reduction to promote densification while minimizing impurities level.
PB  - American Ceramic Society
C3  - Abstract Book / 47th International Conference & Exposition on Advanced Ceramics and Composites, January 22–27, 2023, Daytona Beach, Florida
T1  - Effect of mechanical activation on carbothermal synthesis and densification of ZrC
SP  - ICACC-S18-025-2023
SP  - 117
EP  - 118
UR  - https://hdl.handle.net/21.15107/rcub_dais_16181
ER  - 

@conference{
author = "Obradović, Nina and Filipović, Suzana and Feng, Lun and Mirković, M. and Fahrenholtz, William G.",
year = "2023",
abstract = "Mixtures of ZrO2 and C were prepared by high-energy ball milling. Powders were milled for times from 0 to 120 minutes in air atmosphere. As milling time increased, surface area of powders increased, indicating significant particle size reduction. Milled powders were densified by spark plasma sintering at 2000 °C. Unmilled powders did not reach full density. Milled powders reached full density, but ZrO2 impurities were found for specimens prepared from powders milled for 60 and 120 minutes. Microstructure analysis showed that grain size was less than 2 microns for powder milled for 15 minutes. Based on densification data and impurities level, milling time of
15 minutes appears to give the best balance of particle size reduction to promote densification while minimizing impurities level.",
publisher = "American Ceramic Society",
journal = "Abstract Book / 47th International Conference & Exposition on Advanced Ceramics and Composites, January 22–27, 2023, Daytona Beach, Florida",
title = "Effect of mechanical activation on carbothermal synthesis and densification of ZrC",
pages = "ICACC-S18-025-2023-117-118",
url = "https://hdl.handle.net/21.15107/rcub_dais_16181"
}

Obradović, N., Filipović, S., Feng, L., Mirković, M.,& Fahrenholtz, W. G.. (2023). Effect of mechanical activation on carbothermal synthesis and densification of ZrC. in Abstract Book / 47th International Conference & Exposition on Advanced Ceramics and Composites, January 22–27, 2023, Daytona Beach, Florida
American Ceramic Society., ICACC-S18-025-2023-118.
https://hdl.handle.net/21.15107/rcub_dais_16181

Obradović N, Filipović S, Feng L, Mirković M, Fahrenholtz WG. Effect of mechanical activation on carbothermal synthesis and densification of ZrC. in Abstract Book / 47th International Conference & Exposition on Advanced Ceramics and Composites, January 22–27, 2023, Daytona Beach, Florida. 2023;:ICACC-S18-025-2023-118.
https://hdl.handle.net/21.15107/rcub_dais_16181 .

Obradović, Nina, Filipović, Suzana, Feng, Lun, Mirković, M., Fahrenholtz, William G., "Effect of mechanical activation on carbothermal synthesis and densification of ZrC" in Abstract Book / 47th International Conference & Exposition on Advanced Ceramics and Composites, January 22–27, 2023, Daytona Beach, Florida (2023):ICACC-S18-025-2023-118,
https://hdl.handle.net/21.15107/rcub_dais_16181 .

TY  - CONF
AU  - Obradović, Nina
AU  - Filipović, Suzana
AU  - Bohannan, Eric W.
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/16212
AB  - Mixtures of ZrO2 and C were prepared by high-energy ball milling. Powders were milled for times from 0 to 120 minutes in air atmosphere. As milling time increased, surface area of powders increased, indicating significant particle size reduction. The thermal treatment cycle included heating at 10 °C/min to 1600 °C followed by an isothermal hold for 2 hours under the vacuum (~20 Pa) in a resistance-heated graphite element furnace. This first step of the process promoted carbothermal reaction of the starting materials.
DSC-TGA was used to follow the carbothermal reaction. The onset temperature does not seem to change for non-activated and activated powders. The change in peak area may be related to the amount of the powder that reacts at this temperature. The catbothermal reaction was split into two parts for powders activated 60 and 120 minutes. Only part of the powder reacts at the initial
reaction, and then higher temperatures are required for full reaction.
PB  - Brno : Central and Eastern European Committee for Thermal Analysis and Calorimetry (CEEC-TAC)
C3  - Book of abstracts of the 7th Central and Eastern European Conference on Thermal Analysis and Calorimetry (CEEC-TAC7)
T1  - Carbothermal reaction of mechanically activated ZrC powders followed by DSC-TGA
SP  - 137
EP  - 137
UR  - https://hdl.handle.net/21.15107/rcub_dais_16212
ER  - 

@conference{
author = "Obradović, Nina and Filipović, Suzana and Bohannan, Eric W. and Fahrenholtz, William G.",
year = "2023",
abstract = "Mixtures of ZrO2 and C were prepared by high-energy ball milling. Powders were milled for times from 0 to 120 minutes in air atmosphere. As milling time increased, surface area of powders increased, indicating significant particle size reduction. The thermal treatment cycle included heating at 10 °C/min to 1600 °C followed by an isothermal hold for 2 hours under the vacuum (~20 Pa) in a resistance-heated graphite element furnace. This first step of the process promoted carbothermal reaction of the starting materials.
DSC-TGA was used to follow the carbothermal reaction. The onset temperature does not seem to change for non-activated and activated powders. The change in peak area may be related to the amount of the powder that reacts at this temperature. The catbothermal reaction was split into two parts for powders activated 60 and 120 minutes. Only part of the powder reacts at the initial
reaction, and then higher temperatures are required for full reaction.",
publisher = "Brno : Central and Eastern European Committee for Thermal Analysis and Calorimetry (CEEC-TAC)",
journal = "Book of abstracts of the 7th Central and Eastern European Conference on Thermal Analysis and Calorimetry (CEEC-TAC7)",
title = "Carbothermal reaction of mechanically activated ZrC powders followed by DSC-TGA",
pages = "137-137",
url = "https://hdl.handle.net/21.15107/rcub_dais_16212"
}

Obradović, N., Filipović, S., Bohannan, E. W.,& Fahrenholtz, W. G.. (2023). Carbothermal reaction of mechanically activated ZrC powders followed by DSC-TGA. in Book of abstracts of the 7th Central and Eastern European Conference on Thermal Analysis and Calorimetry (CEEC-TAC7)
Brno : Central and Eastern European Committee for Thermal Analysis and Calorimetry (CEEC-TAC)., 137-137.
https://hdl.handle.net/21.15107/rcub_dais_16212

Obradović N, Filipović S, Bohannan EW, Fahrenholtz WG. Carbothermal reaction of mechanically activated ZrC powders followed by DSC-TGA. in Book of abstracts of the 7th Central and Eastern European Conference on Thermal Analysis and Calorimetry (CEEC-TAC7). 2023;:137-137.
https://hdl.handle.net/21.15107/rcub_dais_16212 .

Obradović, Nina, Filipović, Suzana, Bohannan, Eric W., Fahrenholtz, William G., "Carbothermal reaction of mechanically activated ZrC powders followed by DSC-TGA" in Book of abstracts of the 7th Central and Eastern European Conference on Thermal Analysis and Calorimetry (CEEC-TAC7) (2023):137-137,
https://hdl.handle.net/21.15107/rcub_dais_16212 .

TY  - JOUR
AU  - Obradović, Nina
AU  - Filipović, Suzana
AU  - Fahrenholtz, William G.
AU  - Marinković, Bojan A.
AU  - Rogan, Jelena
AU  - Lević, Steva
AU  - Đorđević, Antonije
AU  - Pavlović, Vladimir B.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/14704
AB  - Magnesium aluminate has the spinel structure along with good mechanical, chemical, and thermal properties. Magnesium aluminate has a wide range of applications including refractory ceramics, optically transparent ceramic windows, and armors. Its low dielectric permeability and low loss tangent enable its applications for integrated electronic devices, as well. In this paper, MgO and Al2O3 powders were mixed in a one-to-one molar ratio and calcined at temperatures ranging from 1500 to 1800°C to produce phase pure spinel. Thereafter, pellets were crushed and treated in a planetary ball mill for 60 min to obtain a fine powder. All powders were examined for phase composition, crystal structure, and morphology. The obtained results showed that by increasing the temperature, samples with higher density were synthesized. Milling for 1 h led to formation of larger particles, but finer powders after milling. XRPD and Raman spectroscopy showed disorder in the crystal structure after milling.
AB  - Магнезијум алуминат поседује структуру спинела и добра механичка, хемијска и термичка својства. Има широк спектар примене, укључујући рефракторну керамику, оружје и оптички транспарентна керамичка стакла. Ниска диелектрична пермеабилност и тангенс губитака пружају овој керамици примену и у електричним направама. У овом раду, прахови MgO и Al2O3 су помешани у моларном односу 1:1 и калцинисани на температурама између 1500°C и 1800°C да би се добио спинел. Након тога, узорци су смрвљени и механички активирани у млину током 60 минута да би се добио фини уситњен прах. Одређени су фазни састав, кристална структура и морфологија свих прахова. Резултати су показали да са порастом температуре расте и густина синтетисаних узорака. Млевење од 1 сата води ка формирању већих честица, али финијих прахова након млевења. XRPD и Раман спектроскопија указују на неуређену кристалну структуру након млевења.
PB  - ETRAN
T2  - Science of Sintering
T1  - Morphological and Structural Characterization of MgAl2O4 Spinel
SP  - 1
EP  - 10
VL  - 55
IS  - 1
DO  - 10.2298/SOS2301001O
UR  - https://hdl.handle.net/21.15107/rcub_dais_14704
ER  - 

@article{
author = "Obradović, Nina and Filipović, Suzana and Fahrenholtz, William G. and Marinković, Bojan A. and Rogan, Jelena and Lević, Steva and Đorđević, Antonije and Pavlović, Vladimir B.",
year = "2023",
abstract = "Magnesium aluminate has the spinel structure along with good mechanical, chemical, and thermal properties. Magnesium aluminate has a wide range of applications including refractory ceramics, optically transparent ceramic windows, and armors. Its low dielectric permeability and low loss tangent enable its applications for integrated electronic devices, as well. In this paper, MgO and Al2O3 powders were mixed in a one-to-one molar ratio and calcined at temperatures ranging from 1500 to 1800°C to produce phase pure spinel. Thereafter, pellets were crushed and treated in a planetary ball mill for 60 min to obtain a fine powder. All powders were examined for phase composition, crystal structure, and morphology. The obtained results showed that by increasing the temperature, samples with higher density were synthesized. Milling for 1 h led to formation of larger particles, but finer powders after milling. XRPD and Raman spectroscopy showed disorder in the crystal structure after milling., Магнезијум алуминат поседује структуру спинела и добра механичка, хемијска и термичка својства. Има широк спектар примене, укључујући рефракторну керамику, оружје и оптички транспарентна керамичка стакла. Ниска диелектрична пермеабилност и тангенс губитака пружају овој керамици примену и у електричним направама. У овом раду, прахови MgO и Al2O3 су помешани у моларном односу 1:1 и калцинисани на температурама између 1500°C и 1800°C да би се добио спинел. Након тога, узорци су смрвљени и механички активирани у млину током 60 минута да би се добио фини уситњен прах. Одређени су фазни састав, кристална структура и морфологија свих прахова. Резултати су показали да са порастом температуре расте и густина синтетисаних узорака. Млевење од 1 сата води ка формирању већих честица, али финијих прахова након млевења. XRPD и Раман спектроскопија указују на неуређену кристалну структуру након млевења.",
publisher = "ETRAN",
journal = "Science of Sintering",
title = "Morphological and Structural Characterization of MgAl2O4 Spinel",
pages = "1-10",
volume = "55",
number = "1",
doi = "10.2298/SOS2301001O",
url = "https://hdl.handle.net/21.15107/rcub_dais_14704"
}

Obradović, N., Filipović, S., Fahrenholtz, W. G., Marinković, B. A., Rogan, J., Lević, S., Đorđević, A.,& Pavlović, V. B.. (2023). Morphological and Structural Characterization of MgAl2O4 Spinel. in Science of Sintering
ETRAN., 55(1), 1-10.
https://doi.org/10.2298/SOS2301001O
https://hdl.handle.net/21.15107/rcub_dais_14704

Obradović N, Filipović S, Fahrenholtz WG, Marinković BA, Rogan J, Lević S, Đorđević A, Pavlović VB. Morphological and Structural Characterization of MgAl2O4 Spinel. in Science of Sintering. 2023;55(1):1-10.
doi:10.2298/SOS2301001O
https://hdl.handle.net/21.15107/rcub_dais_14704 .

Obradović, Nina, Filipović, Suzana, Fahrenholtz, William G., Marinković, Bojan A., Rogan, Jelena, Lević, Steva, Đorđević, Antonije, Pavlović, Vladimir B., "Morphological and Structural Characterization of MgAl2O4 Spinel" in Science of Sintering, 55, no. 1 (2023):1-10,
https://doi.org/10.2298/SOS2301001O .,
https://hdl.handle.net/21.15107/rcub_dais_14704 .

TY  - JOUR
AU  - Silvestroni, Laura
AU  - Gilli, Nicola
AU  - Sangiorgi, Alex
AU  - Corozzi, Alessandro
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Ortiz-Membrado, Laia
AU  - Jiménez-Piqué, Emilio
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/14009
AB  - Multi-phase ceramics based on ZrB2, TiB2 and doped with CrB2 and SiC were prepared by powder metallurgy and hot pressing to explore the possibility of obtaining multi-scale microstructures by super-saturation of complex (Zr,Ti,Cr)B2 solid solutions. Core–shell structures formed in TiB2 grains, whereas ZrB2 appeared to form a homogeneous solid solution with the other metals. Precipitation of nano-inclusions within both micron-sized borides was assessed by transmission electron microscopy and thermodynamics elucidated the preferential formation of boride inclusions due to the specific sintering atmosphere. In addition, atomic size factors explicated the precipitation of CrB2 nano-particles into ZrB2-rich grains and of ZrB2 nano-particles into TiB2-rich grains. The hardness of the constituent phases measured by nanoindentation ranged from 36 to 43 GPa.
PB  - Tsinghua University Press
T2  - Journal of Advanced Ceramics
T1  - Multi-phase (Zr,Ti,Cr)B2solid solutions: Preparation, multi-scale microstructure, and local properties
SP  - 414
EP  - 431
VL  - 12
IS  - 2
DO  - 10.26599/JAC.2023.9220695
UR  - https://hdl.handle.net/21.15107/rcub_dais_14009
ER  - 

@article{
author = "Silvestroni, Laura and Gilli, Nicola and Sangiorgi, Alex and Corozzi, Alessandro and Filipović, Suzana and Obradović, Nina and Ortiz-Membrado, Laia and Jiménez-Piqué, Emilio and Fahrenholtz, William G.",
year = "2023",
abstract = "Multi-phase ceramics based on ZrB2, TiB2 and doped with CrB2 and SiC were prepared by powder metallurgy and hot pressing to explore the possibility of obtaining multi-scale microstructures by super-saturation of complex (Zr,Ti,Cr)B2 solid solutions. Core–shell structures formed in TiB2 grains, whereas ZrB2 appeared to form a homogeneous solid solution with the other metals. Precipitation of nano-inclusions within both micron-sized borides was assessed by transmission electron microscopy and thermodynamics elucidated the preferential formation of boride inclusions due to the specific sintering atmosphere. In addition, atomic size factors explicated the precipitation of CrB2 nano-particles into ZrB2-rich grains and of ZrB2 nano-particles into TiB2-rich grains. The hardness of the constituent phases measured by nanoindentation ranged from 36 to 43 GPa.",
publisher = "Tsinghua University Press",
journal = "Journal of Advanced Ceramics",
title = "Multi-phase (Zr,Ti,Cr)B2solid solutions: Preparation, multi-scale microstructure, and local properties",
pages = "414-431",
volume = "12",
number = "2",
doi = "10.26599/JAC.2023.9220695",
url = "https://hdl.handle.net/21.15107/rcub_dais_14009"
}

Silvestroni, L., Gilli, N., Sangiorgi, A., Corozzi, A., Filipović, S., Obradović, N., Ortiz-Membrado, L., Jiménez-Piqué, E.,& Fahrenholtz, W. G.. (2023). Multi-phase (Zr,Ti,Cr)B2solid solutions: Preparation, multi-scale microstructure, and local properties. in Journal of Advanced Ceramics
Tsinghua University Press., 12(2), 414-431.
https://doi.org/10.26599/JAC.2023.9220695
https://hdl.handle.net/21.15107/rcub_dais_14009

Silvestroni L, Gilli N, Sangiorgi A, Corozzi A, Filipović S, Obradović N, Ortiz-Membrado L, Jiménez-Piqué E, Fahrenholtz WG. Multi-phase (Zr,Ti,Cr)B2solid solutions: Preparation, multi-scale microstructure, and local properties. in Journal of Advanced Ceramics. 2023;12(2):414-431.
doi:10.26599/JAC.2023.9220695
https://hdl.handle.net/21.15107/rcub_dais_14009 .

Silvestroni, Laura, Gilli, Nicola, Sangiorgi, Alex, Corozzi, Alessandro, Filipović, Suzana, Obradović, Nina, Ortiz-Membrado, Laia, Jiménez-Piqué, Emilio, Fahrenholtz, William G., "Multi-phase (Zr,Ti,Cr)B2solid solutions: Preparation, multi-scale microstructure, and local properties" in Journal of Advanced Ceramics, 12, no. 2 (2023):414-431,
https://doi.org/10.26599/JAC.2023.9220695 .,
https://hdl.handle.net/21.15107/rcub_dais_14009 .

TY  - JOUR
AU  - Obradović, Nina
AU  - Feng, Lun
AU  - Filipović, Suzana
AU  - Mirković, Miljana
AU  - Kosanović, Darko
AU  - Rogan, Jelena
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/14890
AB  - Zirconium carbide ceramics were prepared by carbothermal reduction of ZrO2 and C that were mixed by high-energy ball milling. Powders were milled for times from 0 to 120 min in air. As milling time increased, the surface area of the powders increased, indicating significant particle size reduction. Milled powders were reacted at 1600 °C and then densified by spark plasma sintering at 2000 °C, which was sufficient to convert the starting powders to zirconium carbide. Unmilled powders did not reach full density. Milled powders reached full density, but ZrO2 impurities were found for specimens prepared from powders milled for 60 and 120 min. Microstructure analysis showed that grain size was less than 2 µm for ceramics produced from powder milled for 15 min. Based on densification onset temperature and impurity levels, a milling time of 15 min gives the best balance of particle size reduction to promote densification while minimizing impurity levels.
PB  - Elsevier BV
T2  - Journal of the European Ceramic Society
T1  - Effect of mechanical activation on carbothermal synthesis and densification of ZrC
SP  - 7306
EP  - 7313
DO  - 10.1016/j.jeurceramsoc.2023.08.007
UR  - https://hdl.handle.net/21.15107/rcub_dais_14890
ER  - 

@article{
author = "Obradović, Nina and Feng, Lun and Filipović, Suzana and Mirković, Miljana and Kosanović, Darko and Rogan, Jelena and Fahrenholtz, William G.",
year = "2023",
abstract = "Zirconium carbide ceramics were prepared by carbothermal reduction of ZrO2 and C that were mixed by high-energy ball milling. Powders were milled for times from 0 to 120 min in air. As milling time increased, the surface area of the powders increased, indicating significant particle size reduction. Milled powders were reacted at 1600 °C and then densified by spark plasma sintering at 2000 °C, which was sufficient to convert the starting powders to zirconium carbide. Unmilled powders did not reach full density. Milled powders reached full density, but ZrO2 impurities were found for specimens prepared from powders milled for 60 and 120 min. Microstructure analysis showed that grain size was less than 2 µm for ceramics produced from powder milled for 15 min. Based on densification onset temperature and impurity levels, a milling time of 15 min gives the best balance of particle size reduction to promote densification while minimizing impurity levels.",
publisher = "Elsevier BV",
journal = "Journal of the European Ceramic Society",
title = "Effect of mechanical activation on carbothermal synthesis and densification of ZrC",
pages = "7306-7313",
doi = "10.1016/j.jeurceramsoc.2023.08.007",
url = "https://hdl.handle.net/21.15107/rcub_dais_14890"
}

Obradović, N., Feng, L., Filipović, S., Mirković, M., Kosanović, D., Rogan, J.,& Fahrenholtz, W. G.. (2023). Effect of mechanical activation on carbothermal synthesis and densification of ZrC. in Journal of the European Ceramic Society
Elsevier BV., 7306-7313.
https://doi.org/10.1016/j.jeurceramsoc.2023.08.007
https://hdl.handle.net/21.15107/rcub_dais_14890

Obradović N, Feng L, Filipović S, Mirković M, Kosanović D, Rogan J, Fahrenholtz WG. Effect of mechanical activation on carbothermal synthesis and densification of ZrC. in Journal of the European Ceramic Society. 2023;:7306-7313.
doi:10.1016/j.jeurceramsoc.2023.08.007
https://hdl.handle.net/21.15107/rcub_dais_14890 .

Obradović, Nina, Feng, Lun, Filipović, Suzana, Mirković, Miljana, Kosanović, Darko, Rogan, Jelena, Fahrenholtz, William G., "Effect of mechanical activation on carbothermal synthesis and densification of ZrC" in Journal of the European Ceramic Society (2023):7306-7313,
https://doi.org/10.1016/j.jeurceramsoc.2023.08.007 .,
https://hdl.handle.net/21.15107/rcub_dais_14890 .

TY  - CONF
AU  - Filipović, Suzana
AU  - Smith, Steven
AU  - Obradović, Nina
AU  - Hilmas, Gregory E.
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/15224
AB  - High entropy carbide/boride (HEC/HEB) ceramics are materials with a wide range of possible applications in harsh environments due to their good mechanical properties, oxidation resistance, and thermal stability. They are usually formed by the solid solutioning of four or more transition metals (TM) in the boride and carbide lattice. In this research, boro/carbothermal reduction was used to form an individual diboride and carbide phases from oxide mixtures. The stoichiometry of the reaction was varied in order to synthesize pure dual phase ceramics. The reacted powders were spark plasma sintered (SPS) or hot pressed (HP), using a two-step process, to produce dense ceramics and to develop the solid solutions. Ceramics processed by SPS still contained residual oxides, while ceramics produced by HP were nominally phase-pure high entropy dual phase materials. Preferential segregation of the TMs was detected by energy dispersive spectroscopy. Vickers hardness measurements confirmed that the highest hardness was obtained for specimens densified by HP at 1950°C that contained no residual oxides and had the smallest grain size. The hardness increased from 25.7 ± 0.2 GPa to 33.6 ± 2.2 GPa with decrease applied load from 9.81N to 0.49N, respectively.
PB  - Belgrade : Serbian Ceramic Society
C3  - Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023.
T1  - Optimization of processing parameters for high entropy dual phase ceramics
SP  - 53
EP  - 53
UR  - https://hdl.handle.net/21.15107/rcub_dais_15224
ER  - 

@conference{
author = "Filipović, Suzana and Smith, Steven and Obradović, Nina and Hilmas, Gregory E. and Fahrenholtz, William G.",
year = "2023",
abstract = "High entropy carbide/boride (HEC/HEB) ceramics are materials with a wide range of possible applications in harsh environments due to their good mechanical properties, oxidation resistance, and thermal stability. They are usually formed by the solid solutioning of four or more transition metals (TM) in the boride and carbide lattice. In this research, boro/carbothermal reduction was used to form an individual diboride and carbide phases from oxide mixtures. The stoichiometry of the reaction was varied in order to synthesize pure dual phase ceramics. The reacted powders were spark plasma sintered (SPS) or hot pressed (HP), using a two-step process, to produce dense ceramics and to develop the solid solutions. Ceramics processed by SPS still contained residual oxides, while ceramics produced by HP were nominally phase-pure high entropy dual phase materials. Preferential segregation of the TMs was detected by energy dispersive spectroscopy. Vickers hardness measurements confirmed that the highest hardness was obtained for specimens densified by HP at 1950°C that contained no residual oxides and had the smallest grain size. The hardness increased from 25.7 ± 0.2 GPa to 33.6 ± 2.2 GPa with decrease applied load from 9.81N to 0.49N, respectively.",
publisher = "Belgrade : Serbian Ceramic Society",
journal = "Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023.",
title = "Optimization of processing parameters for high entropy dual phase ceramics",
pages = "53-53",
url = "https://hdl.handle.net/21.15107/rcub_dais_15224"
}

Filipović, S., Smith, S., Obradović, N., Hilmas, G. E.,& Fahrenholtz, W. G.. (2023). Optimization of processing parameters for high entropy dual phase ceramics. in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023.
Belgrade : Serbian Ceramic Society., 53-53.
https://hdl.handle.net/21.15107/rcub_dais_15224

Filipović S, Smith S, Obradović N, Hilmas GE, Fahrenholtz WG. Optimization of processing parameters for high entropy dual phase ceramics. in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023.. 2023;:53-53.
https://hdl.handle.net/21.15107/rcub_dais_15224 .

Filipović, Suzana, Smith, Steven, Obradović, Nina, Hilmas, Gregory E., Fahrenholtz, William G., "Optimization of processing parameters for high entropy dual phase ceramics" in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023. (2023):53-53,
https://hdl.handle.net/21.15107/rcub_dais_15224 .

TY  - CONF
AU  - Kosanović, Darko
AU  - Fahrenholtz, William G.
AU  - Obradović, Nina
AU  - Filipović, Suzana
AU  - Watts, Jeremy L.
AU  - Hilmas, G. E.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/15009
AB  - The thermal properties of zirconium diboride (ZrB2) ceramics with tungsten additions of up to 5 wt% were characterized up to 2000°C. Densification was promoted by the addition of 0.5 wt% carbon. ZrB2 ceramics were prepared from commercially available powder by hot pressing. The crystalline phases present were determined by x-ray diffraction. The microstructure and density change as a result of the addition of tungsten, but this does not affect much the thermal behavior of ZrB2 at room and elevated temperatures. Thermal diffusivity at 200°C decreased from 0.158 cm2/s for nominally pure ZrB2 to 0.149 cm2/s for ZrB2 with 5 wt% Tungsten carbide (WC). The thermal diffusivity decreased with increasing temperature, reaching a value of 0.145 cm2/s at 2000°C for ZrB2 with 5 wt% Tungsten carbide (WC). Heat capacity, unlike thermal diffusivity, did not change during thermal cycling. Thermal conductivity, which was calculated from thermal diffusivity, heat capacity, and density, was as high as 77.9 W/(m·K) at 2000°C for ZrB2 with 5 wt% Tungsten carbide (WC). Any level of Tungsten carbide (WC) contamination reduces thermal conductivity. Properties, including hardness, oxygen content, elastic modulus, strength were measured and will be discussed.
PB  - Belgrade : University of Belgrade - Faculty of Mechanical Engineering
C3  - Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia
T1  - Elevated Temperature Thermal Properties of ZrB2 with Tungsten Additions
SP  - 79
UR  - https://hdl.handle.net/21.15107/rcub_dais_15009
ER  - 

@conference{
author = "Kosanović, Darko and Fahrenholtz, William G. and Obradović, Nina and Filipović, Suzana and Watts, Jeremy L. and Hilmas, G. E.",
year = "2023",
abstract = "The thermal properties of zirconium diboride (ZrB2) ceramics with tungsten additions of up to 5 wt% were characterized up to 2000°C. Densification was promoted by the addition of 0.5 wt% carbon. ZrB2 ceramics were prepared from commercially available powder by hot pressing. The crystalline phases present were determined by x-ray diffraction. The microstructure and density change as a result of the addition of tungsten, but this does not affect much the thermal behavior of ZrB2 at room and elevated temperatures. Thermal diffusivity at 200°C decreased from 0.158 cm2/s for nominally pure ZrB2 to 0.149 cm2/s for ZrB2 with 5 wt% Tungsten carbide (WC). The thermal diffusivity decreased with increasing temperature, reaching a value of 0.145 cm2/s at 2000°C for ZrB2 with 5 wt% Tungsten carbide (WC). Heat capacity, unlike thermal diffusivity, did not change during thermal cycling. Thermal conductivity, which was calculated from thermal diffusivity, heat capacity, and density, was as high as 77.9 W/(m·K) at 2000°C for ZrB2 with 5 wt% Tungsten carbide (WC). Any level of Tungsten carbide (WC) contamination reduces thermal conductivity. Properties, including hardness, oxygen content, elastic modulus, strength were measured and will be discussed.",
publisher = "Belgrade : University of Belgrade - Faculty of Mechanical Engineering",
journal = "Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia",
title = "Elevated Temperature Thermal Properties of ZrB2 with Tungsten Additions",
pages = "79",
url = "https://hdl.handle.net/21.15107/rcub_dais_15009"
}

Kosanović, D., Fahrenholtz, W. G., Obradović, N., Filipović, S., Watts, J. L.,& Hilmas, G. E.. (2023). Elevated Temperature Thermal Properties of ZrB2 with Tungsten Additions. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia
Belgrade : University of Belgrade - Faculty of Mechanical Engineering., 79.
https://hdl.handle.net/21.15107/rcub_dais_15009

Kosanović D, Fahrenholtz WG, Obradović N, Filipović S, Watts JL, Hilmas GE. Elevated Temperature Thermal Properties of ZrB2 with Tungsten Additions. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia. 2023;:79.
https://hdl.handle.net/21.15107/rcub_dais_15009 .

Kosanović, Darko, Fahrenholtz, William G., Obradović, Nina, Filipović, Suzana, Watts, Jeremy L., Hilmas, G. E., "Elevated Temperature Thermal Properties of ZrB2 with Tungsten Additions" in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia (2023):79,
https://hdl.handle.net/21.15107/rcub_dais_15009 .

TY  - CONF
AU  - Obradović, Nina
AU  - Feng, Lun
AU  - Filipović, Suzana
AU  - Mirković, M.
AU  - Kosanović, Darko
AU  - Živojinović, Jelena
AU  - Rogan, Jelena
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/15008
AB  - Mechanical activation represents a very useful technique for powder processing prior to sintering process. First of all, it makes powders homogenized, leads to attrition of powder particles, and makes powder mixtures more reactive. Secondly, it can lead to mechano-chemical reaction, and finally, lowering of sintering time and temperature. Mixtures of ZrO2 and C were mechanically activated by high-energy ball milling. Powders were milled for times from 0 to 120 minutes in air atmosphere. Mechanically activated powder mixtures were characterized by various techniques, such as particle size analysis (PSA), X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, and diffraction scanning calorimetry along with thermo gravimetry (DSC-TGA). As milling time increased, surface area of powders increased, indicating significant particle size reduction. Mechanical activation for 15 minutes provides the best balance between particle size reduction and reactivity for the powders.
PB  - Belgrade : University of Belgrade - Faculty of Mechanical Engineering
C3  - Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia
T1  - Characterization of mechanically activated ZrO2-C powder mixtures
SP  - 78
UR  - https://hdl.handle.net/21.15107/rcub_dais_15008
ER  - 

@conference{
author = "Obradović, Nina and Feng, Lun and Filipović, Suzana and Mirković, M. and Kosanović, Darko and Živojinović, Jelena and Rogan, Jelena and Fahrenholtz, William G.",
year = "2023",
abstract = "Mechanical activation represents a very useful technique for powder processing prior to sintering process. First of all, it makes powders homogenized, leads to attrition of powder particles, and makes powder mixtures more reactive. Secondly, it can lead to mechano-chemical reaction, and finally, lowering of sintering time and temperature. Mixtures of ZrO2 and C were mechanically activated by high-energy ball milling. Powders were milled for times from 0 to 120 minutes in air atmosphere. Mechanically activated powder mixtures were characterized by various techniques, such as particle size analysis (PSA), X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, and diffraction scanning calorimetry along with thermo gravimetry (DSC-TGA). As milling time increased, surface area of powders increased, indicating significant particle size reduction. Mechanical activation for 15 minutes provides the best balance between particle size reduction and reactivity for the powders.",
publisher = "Belgrade : University of Belgrade - Faculty of Mechanical Engineering",
journal = "Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia",
title = "Characterization of mechanically activated ZrO2-C powder mixtures",
pages = "78",
url = "https://hdl.handle.net/21.15107/rcub_dais_15008"
}

Obradović, N., Feng, L., Filipović, S., Mirković, M., Kosanović, D., Živojinović, J., Rogan, J.,& Fahrenholtz, W. G.. (2023). Characterization of mechanically activated ZrO2-C powder mixtures. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia
Belgrade : University of Belgrade - Faculty of Mechanical Engineering., 78.
https://hdl.handle.net/21.15107/rcub_dais_15008

Obradović N, Feng L, Filipović S, Mirković M, Kosanović D, Živojinović J, Rogan J, Fahrenholtz WG. Characterization of mechanically activated ZrO2-C powder mixtures. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia. 2023;:78.
https://hdl.handle.net/21.15107/rcub_dais_15008 .

Obradović, Nina, Feng, Lun, Filipović, Suzana, Mirković, M., Kosanović, Darko, Živojinović, Jelena, Rogan, Jelena, Fahrenholtz, William G., "Characterization of mechanically activated ZrO2-C powder mixtures" in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia (2023):78,
https://hdl.handle.net/21.15107/rcub_dais_15008 .

TY  - CONF
AU  - Kosanović, Darko
AU  - Filipović, Suzana
AU  - Trajković, Isaak
AU  - Obradović, Nina
AU  - Brune, Paul M.
AU  - Hilmas, Gregory E.
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/15006
AB  - Zirconium diboride(ZrB2) belongs to the group of ultrahigh temperature ceramics (UHTCs) because of its high melting point (3250°C). Due to its excellent properties, such as the melting temperature, high strength and hardness, high thermal and electrical conductivities relative to other ceramics and good corrosion resistance to molten metals, it has attracted great interest from materials scientists. Fully dense ZrB2 ceramics were successfully obtained by hot pressing at 2150oC for 10 minutes. Prior to hot pressing, commercially available ZrB2 powder was ball milled for 24hr with ZrB2 media. Carbon was added as a densification aid in the amount of 0.5 wt.% using phenolic resin. For mechanical testing, three different methods were compared. Three point bending was performed in air at room temperature and the obtained strength was 546±55 MPa. Four-point bend strengths were measured under same conditions resulting in strengths of 476±112 MPa. Finally, the fracture toughness of pure ZrB2 ceramics was determined by the chevron notched beam method to be 4.1 ± 0.5 MPa•m1/2. The obtained results of mechanical testing make this ceramic material applicable as cutting tools, and parts for hypersonic aerospace vehicles.
PB  - Belgrade : Serbian Ceramic Society
C3  - Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023
T1  - Mechanical properties of zirconium diboride ceramics
SP  - 84
UR  - https://hdl.handle.net/21.15107/rcub_dais_15006
ER  - 

@conference{
author = "Kosanović, Darko and Filipović, Suzana and Trajković, Isaak and Obradović, Nina and Brune, Paul M. and Hilmas, Gregory E. and Fahrenholtz, William G.",
year = "2023",
abstract = "Zirconium diboride(ZrB2) belongs to the group of ultrahigh temperature ceramics (UHTCs) because of its high melting point (3250°C). Due to its excellent properties, such as the melting temperature, high strength and hardness, high thermal and electrical conductivities relative to other ceramics and good corrosion resistance to molten metals, it has attracted great interest from materials scientists. Fully dense ZrB2 ceramics were successfully obtained by hot pressing at 2150oC for 10 minutes. Prior to hot pressing, commercially available ZrB2 powder was ball milled for 24hr with ZrB2 media. Carbon was added as a densification aid in the amount of 0.5 wt.% using phenolic resin. For mechanical testing, three different methods were compared. Three point bending was performed in air at room temperature and the obtained strength was 546±55 MPa. Four-point bend strengths were measured under same conditions resulting in strengths of 476±112 MPa. Finally, the fracture toughness of pure ZrB2 ceramics was determined by the chevron notched beam method to be 4.1 ± 0.5 MPa•m1/2. The obtained results of mechanical testing make this ceramic material applicable as cutting tools, and parts for hypersonic aerospace vehicles.",
publisher = "Belgrade : Serbian Ceramic Society",
journal = "Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023",
title = "Mechanical properties of zirconium diboride ceramics",
pages = "84",
url = "https://hdl.handle.net/21.15107/rcub_dais_15006"
}

Kosanović, D., Filipović, S., Trajković, I., Obradović, N., Brune, P. M., Hilmas, G. E.,& Fahrenholtz, W. G.. (2023). Mechanical properties of zirconium diboride ceramics. in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023
Belgrade : Serbian Ceramic Society., 84.
https://hdl.handle.net/21.15107/rcub_dais_15006

Kosanović D, Filipović S, Trajković I, Obradović N, Brune PM, Hilmas GE, Fahrenholtz WG. Mechanical properties of zirconium diboride ceramics. in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023. 2023;:84.
https://hdl.handle.net/21.15107/rcub_dais_15006 .

Kosanović, Darko, Filipović, Suzana, Trajković, Isaak, Obradović, Nina, Brune, Paul M., Hilmas, Gregory E., Fahrenholtz, William G., "Mechanical properties of zirconium diboride ceramics" in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023 (2023):84,
https://hdl.handle.net/21.15107/rcub_dais_15006 .

TY  - CONF
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Fahrenholtz, William G.
AU  - Smith, Steven
AU  - Mirković, M.
AU  - Peleš Tadić, Adriana
AU  - Tadić, Nenad
AU  - Đorđević, Antonije
PY  - 2022
UR  - https://dais.sanu.ac.rs/123456789/13622
AB  - Perovskite ceramic material based on MgTiO3 is used in various types of electronic devices owing to its dielectric properties, high dielectric constant, and low losses. These features can be tailored by setting preparation conditions. Densification of magnesium titanate by Spark Plasma Sintering (SPS) was the aim of this work. First, the mechanical activation in the highenergy ball mill was applied on the powder of MgO-TiO2 mixed in mole ratio 1:1. Prepared powder mixtures, activated for different times, were SPS sintered, at 1200 oC with a heating rate of 100oC/min. After reaching the desired temperature, a uniaxial pressure of 50 MPa was applied, and dwelled at this condition for 5 min, followed by cooling to room temperature at 5oC/min. The starting powders, activated mixtures, and sintered ceramics bodies were investigated by X-ray diffraction, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The presence of the MgTi2O5 phase was noticed for the nonmilled ceramics. In the samples obtained from milled powders, MgTi2O5 was detected in EDS spectra in a lower amount, below the threshold of the XRD method. Dielectric measurements were performed at a wide range of frequencies and temperatures. The highest value of the hardness was obtained from powder milled for 15 min before SPS.
PB  - Belgrade : Serbian Ceramic Society
C3  - Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application X New Frontiers in Multifunctional Material Science and Processing, Serbia, Belgrade, 26-27. September 2022.
T1  - Effect of high energy ball milling on sintering of MgO-TiO2 system
SP  - 88
EP  - 88
UR  - https://hdl.handle.net/21.15107/rcub_dais_13622
ER  - 

@conference{
author = "Filipović, Suzana and Obradović, Nina and Fahrenholtz, William G. and Smith, Steven and Mirković, M. and Peleš Tadić, Adriana and Tadić, Nenad and Đorđević, Antonije",
year = "2022",
abstract = "Perovskite ceramic material based on MgTiO3 is used in various types of electronic devices owing to its dielectric properties, high dielectric constant, and low losses. These features can be tailored by setting preparation conditions. Densification of magnesium titanate by Spark Plasma Sintering (SPS) was the aim of this work. First, the mechanical activation in the highenergy ball mill was applied on the powder of MgO-TiO2 mixed in mole ratio 1:1. Prepared powder mixtures, activated for different times, were SPS sintered, at 1200 oC with a heating rate of 100oC/min. After reaching the desired temperature, a uniaxial pressure of 50 MPa was applied, and dwelled at this condition for 5 min, followed by cooling to room temperature at 5oC/min. The starting powders, activated mixtures, and sintered ceramics bodies were investigated by X-ray diffraction, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The presence of the MgTi2O5 phase was noticed for the nonmilled ceramics. In the samples obtained from milled powders, MgTi2O5 was detected in EDS spectra in a lower amount, below the threshold of the XRD method. Dielectric measurements were performed at a wide range of frequencies and temperatures. The highest value of the hardness was obtained from powder milled for 15 min before SPS.",
publisher = "Belgrade : Serbian Ceramic Society",
journal = "Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application X New Frontiers in Multifunctional Material Science and Processing, Serbia, Belgrade, 26-27. September 2022.",
title = "Effect of high energy ball milling on sintering of MgO-TiO2 system",
pages = "88-88",
url = "https://hdl.handle.net/21.15107/rcub_dais_13622"
}

Filipović, S., Obradović, N., Fahrenholtz, W. G., Smith, S., Mirković, M., Peleš Tadić, A., Tadić, N.,& Đorđević, A.. (2022). Effect of high energy ball milling on sintering of MgO-TiO2 system. in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application X New Frontiers in Multifunctional Material Science and Processing, Serbia, Belgrade, 26-27. September 2022.
Belgrade : Serbian Ceramic Society., 88-88.
https://hdl.handle.net/21.15107/rcub_dais_13622

Filipović S, Obradović N, Fahrenholtz WG, Smith S, Mirković M, Peleš Tadić A, Tadić N, Đorđević A. Effect of high energy ball milling on sintering of MgO-TiO2 system. in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application X New Frontiers in Multifunctional Material Science and Processing, Serbia, Belgrade, 26-27. September 2022.. 2022;:88-88.
https://hdl.handle.net/21.15107/rcub_dais_13622 .

Filipović, Suzana, Obradović, Nina, Fahrenholtz, William G., Smith, Steven, Mirković, M., Peleš Tadić, Adriana, Tadić, Nenad, Đorđević, Antonije, "Effect of high energy ball milling on sintering of MgO-TiO2 system" in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application X New Frontiers in Multifunctional Material Science and Processing, Serbia, Belgrade, 26-27. September 2022. (2022):88-88,
https://hdl.handle.net/21.15107/rcub_dais_13622 .

TY  - CONF
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Fahrenholtz, William G.
AU  - Smith, Steven
AU  - Mirković, Miljana M.
AU  - Peleš, Adriana
AU  - Đorđević, Antonije
PY  - 2022
UR  - https://dais.sanu.ac.rs/123456789/13118
AB  - MgTiO3 is a material often used in different types of high-frequency capacitors, temperature compensating capacitors, and chip capacitors, so the enhancement of this material is still the focus of many research groups due to its remarkable dielectric properties. Outstanding features can only be achieved when the ceramics are highly dense. Densification of magnesium titanate by Spark Plasma Sintering (SPS) was the aim of this work. Magnesium titanate ceramics were prepared by applying mechanical activation as the first step. Powders prepared in this way were SPS sintered, at 1200 °C with a heating rate of 100 °C/min. After reaching the desired temperature, a uniaxial pressure of 50 MPa was applied. The dwell time at this condition was 5 min, followed by cooling to room temperature at 5°C/min. X-ray diffraction was performed in order to establish the phase composition of milled powders and obtained ceramics. Differences between samples milled in various times intervals, as well as sintered ceramics were examined by means of scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The presence of MgTiz0s phase was detected in XRD and was confirmed by EDS analysis for the non-milled ceramics. In the samples obtained from milled powders, no MgTi2O5 was detected in XRD patterns, but this phase was detected in EDS spectra in a lower amount. Dielectric measurements were performed at a wide range of frequencies, while the hardness of the SPS samples was measured at loads up to 10 N. The highest value of the hardness was obtained from powder milled for 15 min before SPS.
PB  - Belgrade : Innovation Center of Faculty of Mechanical Engineering
C3  - Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2022, 05-08 July 2022, Zlatibor, Serbia
T1  - Spark plasma sintering of mechanically activated MGO-TiO2 system
SP  - 81
EP  - 81
UR  - https://hdl.handle.net/21.15107/rcub_dais_13118
ER  - 

@conference{
author = "Filipović, Suzana and Obradović, Nina and Fahrenholtz, William G. and Smith, Steven and Mirković, Miljana M. and Peleš, Adriana and Đorđević, Antonije",
year = "2022",
abstract = "MgTiO3 is a material often used in different types of high-frequency capacitors, temperature compensating capacitors, and chip capacitors, so the enhancement of this material is still the focus of many research groups due to its remarkable dielectric properties. Outstanding features can only be achieved when the ceramics are highly dense. Densification of magnesium titanate by Spark Plasma Sintering (SPS) was the aim of this work. Magnesium titanate ceramics were prepared by applying mechanical activation as the first step. Powders prepared in this way were SPS sintered, at 1200 °C with a heating rate of 100 °C/min. After reaching the desired temperature, a uniaxial pressure of 50 MPa was applied. The dwell time at this condition was 5 min, followed by cooling to room temperature at 5°C/min. X-ray diffraction was performed in order to establish the phase composition of milled powders and obtained ceramics. Differences between samples milled in various times intervals, as well as sintered ceramics were examined by means of scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The presence of MgTiz0s phase was detected in XRD and was confirmed by EDS analysis for the non-milled ceramics. In the samples obtained from milled powders, no MgTi2O5 was detected in XRD patterns, but this phase was detected in EDS spectra in a lower amount. Dielectric measurements were performed at a wide range of frequencies, while the hardness of the SPS samples was measured at loads up to 10 N. The highest value of the hardness was obtained from powder milled for 15 min before SPS.",
publisher = "Belgrade : Innovation Center of Faculty of Mechanical Engineering",
journal = "Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2022, 05-08 July 2022, Zlatibor, Serbia",
title = "Spark plasma sintering of mechanically activated MGO-TiO2 system",
pages = "81-81",
url = "https://hdl.handle.net/21.15107/rcub_dais_13118"
}

Filipović, S., Obradović, N., Fahrenholtz, W. G., Smith, S., Mirković, M. M., Peleš, A.,& Đorđević, A.. (2022). Spark plasma sintering of mechanically activated MGO-TiO2 system. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2022, 05-08 July 2022, Zlatibor, Serbia
Belgrade : Innovation Center of Faculty of Mechanical Engineering., 81-81.
https://hdl.handle.net/21.15107/rcub_dais_13118

Filipović S, Obradović N, Fahrenholtz WG, Smith S, Mirković MM, Peleš A, Đorđević A. Spark plasma sintering of mechanically activated MGO-TiO2 system. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2022, 05-08 July 2022, Zlatibor, Serbia. 2022;:81-81.
https://hdl.handle.net/21.15107/rcub_dais_13118 .

Filipović, Suzana, Obradović, Nina, Fahrenholtz, William G., Smith, Steven, Mirković, Miljana M., Peleš, Adriana, Đorđević, Antonije, "Spark plasma sintering of mechanically activated MGO-TiO2 system" in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2022, 05-08 July 2022, Zlatibor, Serbia (2022):81-81,
https://hdl.handle.net/21.15107/rcub_dais_13118 .

TY  - CONF
AU  - Silvestroni, Laura
AU  - Gilli, Nicola
AU  - Obradović, Nina
AU  - Filipović, Suzana
AU  - Watts, Jeremy L.
AU  - Fahrenholtz, William G.
PY  - 2022
UR  - https://dais.sanu.ac.rs/123456789/13617
AB  - ZrB2 is widely recognized as the most prominent ultra-high temperature ceramic for aerospace applications, in view of its melting point above 3000°C, and despite it exhibits lower oxidation and ablation resistance as compared to HfB2, it has a much lower density. The addition of TiB2 further lowers the overall weight, which is a relevant factor for materials intended to flight, but it also worsen the oxidation resistance. In this work, different Mecompounds, where Me = Nb, Hf, Cr, V, are added to the ZrB2-TiB2 system to study their effect on the densification, microstructure and thermo-mechanical properties. By adjusting the processing and sintering cycles, fully dense multi-phase ceramics with density in the 5.3-5.7 g/cm3 range and hardness close to 24 GPa have been obtained. A common feature to all materials, is the formation of solid solutions and microstructural details obtained by x-ray diffraction, scanning and electron microscopy are highlighted. Particularly, we explored the nanotexturing of the shell within micron-sized boride grains of the matrix, which resulted from the preferential precipitation of Me-compounds with poor solubility within ZrB2 or TiB2 lattice. Preliminary bending strength and oxidation behavior of these intricate bulk multiphase ceramics are also provided.
PB  - Belgrade : Serbian Ceramic Society
C3  - Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application X New Frontiers in Multifunctional Material Science and Processing, Serbia, Belgrade, 26-27. September 2022.
T1  - Multi-phase (Zr,Ti,Me)B2 solid solutions: preparation and microstructure evolution
SP  - 37
EP  - 37
UR  - https://hdl.handle.net/21.15107/rcub_dais_13617
ER  - 

@conference{
author = "Silvestroni, Laura and Gilli, Nicola and Obradović, Nina and Filipović, Suzana and Watts, Jeremy L. and Fahrenholtz, William G.",
year = "2022",
abstract = "ZrB2 is widely recognized as the most prominent ultra-high temperature ceramic for aerospace applications, in view of its melting point above 3000°C, and despite it exhibits lower oxidation and ablation resistance as compared to HfB2, it has a much lower density. The addition of TiB2 further lowers the overall weight, which is a relevant factor for materials intended to flight, but it also worsen the oxidation resistance. In this work, different Mecompounds, where Me = Nb, Hf, Cr, V, are added to the ZrB2-TiB2 system to study their effect on the densification, microstructure and thermo-mechanical properties. By adjusting the processing and sintering cycles, fully dense multi-phase ceramics with density in the 5.3-5.7 g/cm3 range and hardness close to 24 GPa have been obtained. A common feature to all materials, is the formation of solid solutions and microstructural details obtained by x-ray diffraction, scanning and electron microscopy are highlighted. Particularly, we explored the nanotexturing of the shell within micron-sized boride grains of the matrix, which resulted from the preferential precipitation of Me-compounds with poor solubility within ZrB2 or TiB2 lattice. Preliminary bending strength and oxidation behavior of these intricate bulk multiphase ceramics are also provided.",
publisher = "Belgrade : Serbian Ceramic Society",
journal = "Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application X New Frontiers in Multifunctional Material Science and Processing, Serbia, Belgrade, 26-27. September 2022.",
title = "Multi-phase (Zr,Ti,Me)B2 solid solutions: preparation and microstructure evolution",
pages = "37-37",
url = "https://hdl.handle.net/21.15107/rcub_dais_13617"
}

Silvestroni, L., Gilli, N., Obradović, N., Filipović, S., Watts, J. L.,& Fahrenholtz, W. G.. (2022). Multi-phase (Zr,Ti,Me)B2 solid solutions: preparation and microstructure evolution. in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application X New Frontiers in Multifunctional Material Science and Processing, Serbia, Belgrade, 26-27. September 2022.
Belgrade : Serbian Ceramic Society., 37-37.
https://hdl.handle.net/21.15107/rcub_dais_13617

Silvestroni L, Gilli N, Obradović N, Filipović S, Watts JL, Fahrenholtz WG. Multi-phase (Zr,Ti,Me)B2 solid solutions: preparation and microstructure evolution. in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application X New Frontiers in Multifunctional Material Science and Processing, Serbia, Belgrade, 26-27. September 2022.. 2022;:37-37.
https://hdl.handle.net/21.15107/rcub_dais_13617 .

Silvestroni, Laura, Gilli, Nicola, Obradović, Nina, Filipović, Suzana, Watts, Jeremy L., Fahrenholtz, William G., "Multi-phase (Zr,Ti,Me)B2 solid solutions: preparation and microstructure evolution" in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application X New Frontiers in Multifunctional Material Science and Processing, Serbia, Belgrade, 26-27. September 2022. (2022):37-37,
https://hdl.handle.net/21.15107/rcub_dais_13617 .

TY  - JOUR
AU  - Corlett, Cole A.
AU  - Frontzek, Matthias D.
AU  - Obradović, Nina
AU  - Watts, Jeremy L.
AU  - Fahrenholtz, William G.
PY  - 2022
UR  - https://dais.sanu.ac.rs/123456789/13516
AB  - The synthesis and crystallographic site occupancy were investigated for MgAl2O4 with and without mechanical activation of the precursor powders. Heating to 1200 °C or higher resulted in the formation of a single spinel phase regardless of whether the powders were mechanically activated or not. Neutron diffraction analysis was used to determine cation site occupancy and revealed that mechanical activation resulted in a lower degree of cation site inversion compared to the nonactivated materials, which indicated that the powders were closer to thermodynamic equilibrium. This is the first study to characterize the effects of mechanical activation on crystallographic site occupancy in magnesium aluminate spinel using neutron diffraction. © 2022 by the authors.
T2  - Materials
T1  - Mechanical Activation and Cation Site Disorder in MgAl2O4
VL  - 15
IS  - 18
DO  - 10.3390/ma15186422
UR  - https://hdl.handle.net/21.15107/rcub_dais_13516
ER  - 

@article{
author = "Corlett, Cole A. and Frontzek, Matthias D. and Obradović, Nina and Watts, Jeremy L. and Fahrenholtz, William G.",
year = "2022",
abstract = "The synthesis and crystallographic site occupancy were investigated for MgAl2O4 with and without mechanical activation of the precursor powders. Heating to 1200 °C or higher resulted in the formation of a single spinel phase regardless of whether the powders were mechanically activated or not. Neutron diffraction analysis was used to determine cation site occupancy and revealed that mechanical activation resulted in a lower degree of cation site inversion compared to the nonactivated materials, which indicated that the powders were closer to thermodynamic equilibrium. This is the first study to characterize the effects of mechanical activation on crystallographic site occupancy in magnesium aluminate spinel using neutron diffraction. © 2022 by the authors.",
journal = "Materials",
title = "Mechanical Activation and Cation Site Disorder in MgAl2O4",
volume = "15",
number = "18",
doi = "10.3390/ma15186422",
url = "https://hdl.handle.net/21.15107/rcub_dais_13516"
}

Corlett, C. A., Frontzek, M. D., Obradović, N., Watts, J. L.,& Fahrenholtz, W. G.. (2022). Mechanical Activation and Cation Site Disorder in MgAl2O4. in Materials, 15(18).
https://doi.org/10.3390/ma15186422
https://hdl.handle.net/21.15107/rcub_dais_13516

Corlett CA, Frontzek MD, Obradović N, Watts JL, Fahrenholtz WG. Mechanical Activation and Cation Site Disorder in MgAl2O4. in Materials. 2022;15(18).
doi:10.3390/ma15186422
https://hdl.handle.net/21.15107/rcub_dais_13516 .

Corlett, Cole A., Frontzek, Matthias D., Obradović, Nina, Watts, Jeremy L., Fahrenholtz, William G., "Mechanical Activation and Cation Site Disorder in MgAl2O4" in Materials, 15, no. 18 (2022),
https://doi.org/10.3390/ma15186422 .,
https://hdl.handle.net/21.15107/rcub_dais_13516 .

TY  - CONF
AU  - Obradović, Nina
AU  - Peleš, Adriana
AU  - Olćan, Dragan
AU  - Fahrenholtz, William G.
AU  - Đorđević, Antonije
AU  - Pavlović, Vladimir B.
PY  - 2021
UR  - https://dais.sanu.ac.rs/123456789/12351
AB  - Our research group has developed a method for measurement of complex relative permittivity of various dielectric materials in the frequency range from around 1 kHz up to several GHz. Material samples have preferably a disk shape. The thicknesses of the samples can be in a wide range, from about 10 μm (thick films) up to several mm. We have designed and manufactured a set of coaxial chambers, which we use as test fixtures. We have also developed two numerical-simulation programs for the electromagnetic analysis of bodies with rotational symmetry. One program is suitable for the low-frequency analysis. It is based on an electrostatic approach. The other program is based on an electrodynamic approach and it is tailored for microwave frequencies. In measurements, we use impedance meters and network analyzers to obtain the input impedance of a chamber with a sample. Thereafter, we implement our software for the electromagnetic modeling to extract the relative permittivity of the measured sample. As examples of verification of our method, we present here results for the relative permittivities of two sets of samples whose sizes are on the extreme limits of the method. The first set comprises poly (vinylidene fluoride) and mechanically activated ZnO nanoparticle composite films, whose relative permittivities are around 1.8. The second set comprises large, high-density samples of spinel (aluminum magnesium oxide) ceramics, sintered under various conditions. The measured relative permittivities of these samples are around 7.5. In all cases, good agreement with other available data has been obtained.
PB  - Belgrade : Innovation Center of Faculty of Mechanical Engineering
C3  - Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2021,29 June - 02 July 2021, Zlatibor, Serbia
T1  - Measurement of dielectric permitivity using coaxial chambers and electromagnetic-modeling software
SP  - 82
EP  - 82
UR  - https://hdl.handle.net/21.15107/rcub_dais_12351
ER  - 

@conference{
author = "Obradović, Nina and Peleš, Adriana and Olćan, Dragan and Fahrenholtz, William G. and Đorđević, Antonije and Pavlović, Vladimir B.",
year = "2021",
abstract = "Our research group has developed a method for measurement of complex relative permittivity of various dielectric materials in the frequency range from around 1 kHz up to several GHz. Material samples have preferably a disk shape. The thicknesses of the samples can be in a wide range, from about 10 μm (thick films) up to several mm. We have designed and manufactured a set of coaxial chambers, which we use as test fixtures. We have also developed two numerical-simulation programs for the electromagnetic analysis of bodies with rotational symmetry. One program is suitable for the low-frequency analysis. It is based on an electrostatic approach. The other program is based on an electrodynamic approach and it is tailored for microwave frequencies. In measurements, we use impedance meters and network analyzers to obtain the input impedance of a chamber with a sample. Thereafter, we implement our software for the electromagnetic modeling to extract the relative permittivity of the measured sample. As examples of verification of our method, we present here results for the relative permittivities of two sets of samples whose sizes are on the extreme limits of the method. The first set comprises poly (vinylidene fluoride) and mechanically activated ZnO nanoparticle composite films, whose relative permittivities are around 1.8. The second set comprises large, high-density samples of spinel (aluminum magnesium oxide) ceramics, sintered under various conditions. The measured relative permittivities of these samples are around 7.5. In all cases, good agreement with other available data has been obtained.",
publisher = "Belgrade : Innovation Center of Faculty of Mechanical Engineering",
journal = "Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2021,29 June - 02 July 2021, Zlatibor, Serbia",
title = "Measurement of dielectric permitivity using coaxial chambers and electromagnetic-modeling software",
pages = "82-82",
url = "https://hdl.handle.net/21.15107/rcub_dais_12351"
}

Obradović, N., Peleš, A., Olćan, D., Fahrenholtz, W. G., Đorđević, A.,& Pavlović, V. B.. (2021). Measurement of dielectric permitivity using coaxial chambers and electromagnetic-modeling software. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2021,29 June - 02 July 2021, Zlatibor, Serbia
Belgrade : Innovation Center of Faculty of Mechanical Engineering., 82-82.
https://hdl.handle.net/21.15107/rcub_dais_12351

Obradović N, Peleš A, Olćan D, Fahrenholtz WG, Đorđević A, Pavlović VB. Measurement of dielectric permitivity using coaxial chambers and electromagnetic-modeling software. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2021,29 June - 02 July 2021, Zlatibor, Serbia. 2021;:82-82.
https://hdl.handle.net/21.15107/rcub_dais_12351 .

Obradović, Nina, Peleš, Adriana, Olćan, Dragan, Fahrenholtz, William G., Đorđević, Antonije, Pavlović, Vladimir B., "Measurement of dielectric permitivity using coaxial chambers and electromagnetic-modeling software" in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2021,29 June - 02 July 2021, Zlatibor, Serbia (2021):82-82,
https://hdl.handle.net/21.15107/rcub_dais_12351 .

TY  - JOUR
AU  - Obradović, Nina
AU  - Fahrenholtz, William G.
AU  - Corlett, Cole
AU  - Filipović, Suzana
AU  - Nikolić, Marko
AU  - Marinković, Bojan A.
AU  - Failla, Simone
AU  - Sciti, Diletta
AU  - Di Rosa, Daniele
AU  - Sani, Elisa
PY  - 2021
UR  - https://dais.sanu.ac.rs/123456789/12431
AB  - Magnesium aluminate and other alumina-based spinels attract attention due to their high hardness, high mechanical strength, and low dielectric constant. MgAl2O4 was produced by a solid-state reaction between MgO and α-Al2O3 powders. Mechanical activation for 30 min in a planetary ball mill was used to increase the reactivity of powders. Yttrium oxide and graphene were added to prevent abnormal grain growth during sintering. Samples were sintered by hot pressing under vacuum at 1450 °C. Phase composition and microstructure of sintered specimens were characterized by X-ray powder diffraction and scanning electron microscopy. Rietveld analysis revealed 100% pure spinel phase in all sintered specimens, and a decrease in crystallite size with the addition of yttria or graphene. Density measurements indicated that the mechanically activated specimen reached 99.6% relative density. Furthermore, the highest solar absorbance and highest spectral selectivity as a function of temperature were detected for the mechanically activated specimen with graphene addition. Mechanical activation is an efficient method to improve densification of MgAl2O4 prepared from mixed oxide powders, while additives improve microstructure and optical properties.
PB  - Basel : MDPI AG
T2  - Materials
T1  - Microstructural and Optical Properties of MgAl2O4 Spinel: Effects of Mechanical Activation, Y2O3 and Graphene Additions
SP  - 7674
VL  - 14
IS  - 24
DO  - 10.3390/ma14247674
UR  - https://hdl.handle.net/21.15107/rcub_dais_12431
ER  - 

@article{
author = "Obradović, Nina and Fahrenholtz, William G. and Corlett, Cole and Filipović, Suzana and Nikolić, Marko and Marinković, Bojan A. and Failla, Simone and Sciti, Diletta and Di Rosa, Daniele and Sani, Elisa",
year = "2021",
abstract = "Magnesium aluminate and other alumina-based spinels attract attention due to their high hardness, high mechanical strength, and low dielectric constant. MgAl2O4 was produced by a solid-state reaction between MgO and α-Al2O3 powders. Mechanical activation for 30 min in a planetary ball mill was used to increase the reactivity of powders. Yttrium oxide and graphene were added to prevent abnormal grain growth during sintering. Samples were sintered by hot pressing under vacuum at 1450 °C. Phase composition and microstructure of sintered specimens were characterized by X-ray powder diffraction and scanning electron microscopy. Rietveld analysis revealed 100% pure spinel phase in all sintered specimens, and a decrease in crystallite size with the addition of yttria or graphene. Density measurements indicated that the mechanically activated specimen reached 99.6% relative density. Furthermore, the highest solar absorbance and highest spectral selectivity as a function of temperature were detected for the mechanically activated specimen with graphene addition. Mechanical activation is an efficient method to improve densification of MgAl2O4 prepared from mixed oxide powders, while additives improve microstructure and optical properties.",
publisher = "Basel : MDPI AG",
journal = "Materials",
title = "Microstructural and Optical Properties of MgAl2O4 Spinel: Effects of Mechanical Activation, Y2O3 and Graphene Additions",
pages = "7674",
volume = "14",
number = "24",
doi = "10.3390/ma14247674",
url = "https://hdl.handle.net/21.15107/rcub_dais_12431"
}

Obradović, N., Fahrenholtz, W. G., Corlett, C., Filipović, S., Nikolić, M., Marinković, B. A., Failla, S., Sciti, D., Di Rosa, D.,& Sani, E.. (2021). Microstructural and Optical Properties of MgAl2O4 Spinel: Effects of Mechanical Activation, Y2O3 and Graphene Additions. in Materials
Basel : MDPI AG., 14(24), 7674.
https://doi.org/10.3390/ma14247674
https://hdl.handle.net/21.15107/rcub_dais_12431

Obradović N, Fahrenholtz WG, Corlett C, Filipović S, Nikolić M, Marinković BA, Failla S, Sciti D, Di Rosa D, Sani E. Microstructural and Optical Properties of MgAl2O4 Spinel: Effects of Mechanical Activation, Y2O3 and Graphene Additions. in Materials. 2021;14(24):7674.
doi:10.3390/ma14247674
https://hdl.handle.net/21.15107/rcub_dais_12431 .

Obradović, Nina, Fahrenholtz, William G., Corlett, Cole, Filipović, Suzana, Nikolić, Marko, Marinković, Bojan A., Failla, Simone, Sciti, Diletta, Di Rosa, Daniele, Sani, Elisa, "Microstructural and Optical Properties of MgAl2O4 Spinel: Effects of Mechanical Activation, Y2O3 and Graphene Additions" in Materials, 14, no. 24 (2021):7674,
https://doi.org/10.3390/ma14247674 .,
https://hdl.handle.net/21.15107/rcub_dais_12431 .