Designing, fabrication and characterization of nanostructured functionally graded HAp/BCP ceramics
Abstract
Nanostructured calcium phosphate functionally graded materials (FGMs) with simultaneous gradients of density, phase composition, and mechanical properties were fabricated by consecutive uniaxial pressing of stoichiometric (SHAp) and calcium deficient (CDHAp) hydroxyapatite powders in multilayered samples and reaction sintering. During sintering procedure SHAp composition remained stable (HAp) while CDHAp was phase transformed in biphasic calcium phosphate (BCP, i.e. HAp+β-TCP) yielding HAp/BCP FGMs. To reduce mismatch stress between adjacent layers, generated during sintering, gradient of phase composition was optimized by introducing intermediate layer(s) made from a mixture of SHAp and CDHAp in an appropriate mass ratio. Optimal processing conditions for preparation of nanostructured ceramics were provided via two-step sintering. High-quality FGMs structure, without delamination, cracks and micro-structural damages was observed by an SEM technique; moreover, a detailed examination by... FE-SEM established the unidirectional (perpendicular with respect to the layers) gradual change of microstructure, from fully dense to ~40% of porosity. Detailed micro-Raman and FTIR spectroscopy studies showed an increase of β-TCP amount along the FGMs height, confirming gradient of phase composition. Mechanical properties measured by microindentation revealed gradual change of microhardness from 650 to 115 HV, with simultaneous change of Young's modulus from 92 to 24 GPa. © 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
Keywords:
sintering / mechanical properties / calcium phosphates / functionally graded materials / nanostructureSource:
Ceramics International, 2015, 41, 2, 2654-2667Publisher:
- Elsevier
Funding / projects:
- Molecular designing of nanoparticles with controlled morphological and physicochemical characteristics and functional materials based on them (RS-45004)
- Bilateral cooperation program between the Republic of Serbia and the Republic of Slovenia, Project 451-03-1251/2012-09/06
Note:
- Peer-reviewed manuscript: https://hdl.handle.net/21.15107/rcub_dais_588
DOI: 10.1016/j.ceramint.2014.10.079
ISSN: 0272-8842
WoS: 000348003100003
Scopus: 2-s2.0-84919458370
Institution/Community
Институт техничких наука САНУ / Institute of Technical Sciences of SASATY - JOUR AU - Marković, Smilja AU - Lukić, Miodrag J. AU - Škapin, Srečo Davor AU - Stojanović, Boban AU - Uskoković, Dragan PY - 2015 UR - https://dais.sanu.ac.rs/123456789/3529 AB - Nanostructured calcium phosphate functionally graded materials (FGMs) with simultaneous gradients of density, phase composition, and mechanical properties were fabricated by consecutive uniaxial pressing of stoichiometric (SHAp) and calcium deficient (CDHAp) hydroxyapatite powders in multilayered samples and reaction sintering. During sintering procedure SHAp composition remained stable (HAp) while CDHAp was phase transformed in biphasic calcium phosphate (BCP, i.e. HAp+β-TCP) yielding HAp/BCP FGMs. To reduce mismatch stress between adjacent layers, generated during sintering, gradient of phase composition was optimized by introducing intermediate layer(s) made from a mixture of SHAp and CDHAp in an appropriate mass ratio. Optimal processing conditions for preparation of nanostructured ceramics were provided via two-step sintering. High-quality FGMs structure, without delamination, cracks and micro-structural damages was observed by an SEM technique; moreover, a detailed examination by FE-SEM established the unidirectional (perpendicular with respect to the layers) gradual change of microstructure, from fully dense to ~40% of porosity. Detailed micro-Raman and FTIR spectroscopy studies showed an increase of β-TCP amount along the FGMs height, confirming gradient of phase composition. Mechanical properties measured by microindentation revealed gradual change of microhardness from 650 to 115 HV, with simultaneous change of Young's modulus from 92 to 24 GPa. © 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved. PB - Elsevier T2 - Ceramics International T1 - Designing, fabrication and characterization of nanostructured functionally graded HAp/BCP ceramics SP - 2654 EP - 2667 VL - 41 IS - 2 DO - 10.1016/j.ceramint.2014.10.079 UR - https://hdl.handle.net/21.15107/rcub_dais_3529 ER -
@article{ author = "Marković, Smilja and Lukić, Miodrag J. and Škapin, Srečo Davor and Stojanović, Boban and Uskoković, Dragan", year = "2015", abstract = "Nanostructured calcium phosphate functionally graded materials (FGMs) with simultaneous gradients of density, phase composition, and mechanical properties were fabricated by consecutive uniaxial pressing of stoichiometric (SHAp) and calcium deficient (CDHAp) hydroxyapatite powders in multilayered samples and reaction sintering. During sintering procedure SHAp composition remained stable (HAp) while CDHAp was phase transformed in biphasic calcium phosphate (BCP, i.e. HAp+β-TCP) yielding HAp/BCP FGMs. To reduce mismatch stress between adjacent layers, generated during sintering, gradient of phase composition was optimized by introducing intermediate layer(s) made from a mixture of SHAp and CDHAp in an appropriate mass ratio. Optimal processing conditions for preparation of nanostructured ceramics were provided via two-step sintering. High-quality FGMs structure, without delamination, cracks and micro-structural damages was observed by an SEM technique; moreover, a detailed examination by FE-SEM established the unidirectional (perpendicular with respect to the layers) gradual change of microstructure, from fully dense to ~40% of porosity. Detailed micro-Raman and FTIR spectroscopy studies showed an increase of β-TCP amount along the FGMs height, confirming gradient of phase composition. Mechanical properties measured by microindentation revealed gradual change of microhardness from 650 to 115 HV, with simultaneous change of Young's modulus from 92 to 24 GPa. © 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.", publisher = "Elsevier", journal = "Ceramics International", title = "Designing, fabrication and characterization of nanostructured functionally graded HAp/BCP ceramics", pages = "2654-2667", volume = "41", number = "2", doi = "10.1016/j.ceramint.2014.10.079", url = "https://hdl.handle.net/21.15107/rcub_dais_3529" }
Marković, S., Lukić, M. J., Škapin, S. D., Stojanović, B.,& Uskoković, D.. (2015). Designing, fabrication and characterization of nanostructured functionally graded HAp/BCP ceramics. in Ceramics International Elsevier., 41(2), 2654-2667. https://doi.org/10.1016/j.ceramint.2014.10.079 https://hdl.handle.net/21.15107/rcub_dais_3529
Marković S, Lukić MJ, Škapin SD, Stojanović B, Uskoković D. Designing, fabrication and characterization of nanostructured functionally graded HAp/BCP ceramics. in Ceramics International. 2015;41(2):2654-2667. doi:10.1016/j.ceramint.2014.10.079 https://hdl.handle.net/21.15107/rcub_dais_3529 .
Marković, Smilja, Lukić, Miodrag J., Škapin, Srečo Davor, Stojanović, Boban, Uskoković, Dragan, "Designing, fabrication and characterization of nanostructured functionally graded HAp/BCP ceramics" in Ceramics International, 41, no. 2 (2015):2654-2667, https://doi.org/10.1016/j.ceramint.2014.10.079 ., https://hdl.handle.net/21.15107/rcub_dais_3529 .