The effect of mechanical activation on synthesis and properties of MgAl2O4 ceramics
Authorized Users Only
2019
Authors
Obradović, Nina
Fahrenholtz, William G.

Filipović, Suzana

Kosanović, Darko

Dapčević, Aleksandra

Đorđević, Antonije

Balać, Igor

Pavlović, Vladimir B.

Article (Published version)

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Magnesium aluminate, MgAl2O4 and other alumina-based spinels are ceramics with high hardness, high melting point and mechanical strenght. Spinels can also be used as dielectrics in microwave applications. The goal of this study was to examine the effects of mechanical activation and sintering temperatures on physico-chemical properties of spinel. MgAl2O4 was produced by solid state reaction between MgO and α-Al2O3. The starting powders were mixed by ball milling to homogenize without significant particle size reduction. Mechanical activation of mixed powders was performed in a high-energy planetary ball mill in air for 1 h. Powders were compacted at 300 MPa. Heat treatments were performed in air, at temperatures ranging from 1200 to 1600 °C with 2 h dwell time, to determine the amount of spinel formation as a function of temperature. Phase composition and microstructure of initial powders and heated samples were determined by means of X-ray diffraction, particle size analysis, and scan...ning electron microscopy. The influences of milling and consolidation parameters were studied by electrical measurements and mechanical characterization. The main conclusion of this study was that mechanical activation for 60 min initiated a mechano-chemical reaction, resulted in spinel formation at much lower temperatures than within non-activated powders, and indicated that final sintering stage started at much lower temperatures for activated powders. Changes in microstructure parameters, as a consequence of mechanical treatment and subsequent heating of investigated powder mixtures, strongly affect electrical and mechanical properties of the final ceramics.
Keywords:
electrical properties / mechanical activation / mechanical properties / microstructure / sintering / spinelSource:
Ceramics International, 2019, 45, 9, 12015-12021Publisher:
- Elsevier
Funding / projects:
- Directed synthesis, structure and properties of multifunctional materials (RS-172057)
- Zero- to Three-Dimensional Nanostructures for Application in Electronics and Renewable Energy Sources: Synthesis, Characterization and Processing (RS-45007)
- Synthesis, processing and applications of nanostructured multifunctional materials with defined properties (RS-45019)
Note:
- Peer-reviewed manuscript: https://hdl.handle.net/21.15107/rcub_dais_5272
Related info:
DOI: 10.1016/j.ceramint.2019.03.095
ISBN: 0272-8842
WoS: 000466253500111
Scopus: 2-s2.0-85062915610
URI
http://www.sciencedirect.com/science/article/pii/S0272884219306340https://dais.sanu.ac.rs/123456789/5763
Institution/Community
Институт техничких наука САНУ / Institute of Technical Sciences of SASATY - JOUR AU - Obradović, Nina AU - Fahrenholtz, William G. AU - Filipović, Suzana AU - Kosanović, Darko AU - Dapčević, Aleksandra AU - Đorđević, Antonije AU - Balać, Igor AU - Pavlović, Vladimir B. PY - 2019 UR - http://www.sciencedirect.com/science/article/pii/S0272884219306340 UR - https://dais.sanu.ac.rs/123456789/5763 AB - Magnesium aluminate, MgAl2O4 and other alumina-based spinels are ceramics with high hardness, high melting point and mechanical strenght. Spinels can also be used as dielectrics in microwave applications. The goal of this study was to examine the effects of mechanical activation and sintering temperatures on physico-chemical properties of spinel. MgAl2O4 was produced by solid state reaction between MgO and α-Al2O3. The starting powders were mixed by ball milling to homogenize without significant particle size reduction. Mechanical activation of mixed powders was performed in a high-energy planetary ball mill in air for 1 h. Powders were compacted at 300 MPa. Heat treatments were performed in air, at temperatures ranging from 1200 to 1600 °C with 2 h dwell time, to determine the amount of spinel formation as a function of temperature. Phase composition and microstructure of initial powders and heated samples were determined by means of X-ray diffraction, particle size analysis, and scanning electron microscopy. The influences of milling and consolidation parameters were studied by electrical measurements and mechanical characterization. The main conclusion of this study was that mechanical activation for 60 min initiated a mechano-chemical reaction, resulted in spinel formation at much lower temperatures than within non-activated powders, and indicated that final sintering stage started at much lower temperatures for activated powders. Changes in microstructure parameters, as a consequence of mechanical treatment and subsequent heating of investigated powder mixtures, strongly affect electrical and mechanical properties of the final ceramics. PB - Elsevier T2 - Ceramics International T1 - The effect of mechanical activation on synthesis and properties of MgAl2O4 ceramics SP - 12015 EP - 12021 VL - 45 IS - 9 DO - 10.1016/j.ceramint.2019.03.095 UR - https://hdl.handle.net/21.15107/rcub_dais_5763 ER -
@article{ author = "Obradović, Nina and Fahrenholtz, William G. and Filipović, Suzana and Kosanović, Darko and Dapčević, Aleksandra and Đorđević, Antonije and Balać, Igor and Pavlović, Vladimir B.", year = "2019", abstract = "Magnesium aluminate, MgAl2O4 and other alumina-based spinels are ceramics with high hardness, high melting point and mechanical strenght. Spinels can also be used as dielectrics in microwave applications. The goal of this study was to examine the effects of mechanical activation and sintering temperatures on physico-chemical properties of spinel. MgAl2O4 was produced by solid state reaction between MgO and α-Al2O3. The starting powders were mixed by ball milling to homogenize without significant particle size reduction. Mechanical activation of mixed powders was performed in a high-energy planetary ball mill in air for 1 h. Powders were compacted at 300 MPa. Heat treatments were performed in air, at temperatures ranging from 1200 to 1600 °C with 2 h dwell time, to determine the amount of spinel formation as a function of temperature. Phase composition and microstructure of initial powders and heated samples were determined by means of X-ray diffraction, particle size analysis, and scanning electron microscopy. The influences of milling and consolidation parameters were studied by electrical measurements and mechanical characterization. The main conclusion of this study was that mechanical activation for 60 min initiated a mechano-chemical reaction, resulted in spinel formation at much lower temperatures than within non-activated powders, and indicated that final sintering stage started at much lower temperatures for activated powders. Changes in microstructure parameters, as a consequence of mechanical treatment and subsequent heating of investigated powder mixtures, strongly affect electrical and mechanical properties of the final ceramics.", publisher = "Elsevier", journal = "Ceramics International", title = "The effect of mechanical activation on synthesis and properties of MgAl2O4 ceramics", pages = "12015-12021", volume = "45", number = "9", doi = "10.1016/j.ceramint.2019.03.095", url = "https://hdl.handle.net/21.15107/rcub_dais_5763" }
Obradović, N., Fahrenholtz, W. G., Filipović, S., Kosanović, D., Dapčević, A., Đorđević, A., Balać, I.,& Pavlović, V. B.. (2019). The effect of mechanical activation on synthesis and properties of MgAl2O4 ceramics. in Ceramics International Elsevier., 45(9), 12015-12021. https://doi.org/10.1016/j.ceramint.2019.03.095 https://hdl.handle.net/21.15107/rcub_dais_5763
Obradović N, Fahrenholtz WG, Filipović S, Kosanović D, Dapčević A, Đorđević A, Balać I, Pavlović VB. The effect of mechanical activation on synthesis and properties of MgAl2O4 ceramics. in Ceramics International. 2019;45(9):12015-12021. doi:10.1016/j.ceramint.2019.03.095 https://hdl.handle.net/21.15107/rcub_dais_5763 .
Obradović, Nina, Fahrenholtz, William G., Filipović, Suzana, Kosanović, Darko, Dapčević, Aleksandra, Đorđević, Antonije, Balać, Igor, Pavlović, Vladimir B., "The effect of mechanical activation on synthesis and properties of MgAl2O4 ceramics" in Ceramics International, 45, no. 9 (2019):12015-12021, https://doi.org/10.1016/j.ceramint.2019.03.095 ., https://hdl.handle.net/21.15107/rcub_dais_5763 .