Effect of Mg and Si co-substitution on microstructure and strength of tricalcium phosphate ceramics
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- 作者：Ismael H. Garc铆a-P谩ez ; Ra煤l Garc铆a Carrodeguas ; Antonio H. De Aza ; Carmen Baud铆n ; Pilar Pena
- 关键词：Tricalcium phosphate ; MgO ; SiO2 ; Microstructure-final ; Mechanical properties ; Bioceramics
- 刊名：Journal of the Mechanical Behavior of Biomedical Materials
- 出版年：February, 2014
- 年：2014
- 卷：30
- 期：Complete
- 页码：1-15
- 全文大小：6259 K
文摘
Magnesium and silicon co-doped tricalcium phosphate (TCP) ceramics with compositions corresponding to 0, 5 and 10 wt% CaMg(SiO3)2 in the system Ca3(PO4)2-CaMg(SiO3)2 were obtained by conventional sintering of compacted mixtures of Ca3(PO4)2, MgO, SiO2 and CaCO3 powders at temperatures between 1100 and 1450 掳C. Microstructural analyses were performed by X-ray diffraction and field emission scanning electron microscopy with energy dispersive spectroscopy. Major phases in the obtained ceramics were 尾- or 伪+尾-tricalcium phosphate containing Mg and Si in solid solution. Certain amounts of liquid were formed during sintering depending on composition and temperature. There were found significant differences in distributions of strength determined by the diametral compression of disc tests (DCDT). Failure strengths were controlled by microstructural defects associated with phase development.
Mg and Si additions were found to be effective to improve densification and associated strength of TCP bioceramics due to the enhancement of sintering by the low viscosity liquids formed. The highest density and strength were obtained for the TCP ceramic containing 5 wt% CaMg(SiO3)2 sintered at 1300 掳C. Cracking and porosity increased at higher temperatures due to grain growth and swelling.