Sintering of tricalcium phosphate–fluorapatite composites by addition of alumina

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• 作者：Foued Ben Ayed ; Jamel Bouaziz
• 关键词：A. Sintering ; B. Composites ; B. Porosity ; D. Al₂O₃ ; Bioceramics
• 刊名：Ceramics International
• 出版年：2008
• 出版时间：December 2008
• 年：2008
• 卷：34
• 期：8
• 页码：1885-1892
• 全文大小：1564 K

文摘

The effect of alumina (Al₂O₃) addition on the densification of tricalcium phosphate–26.52 wt % fluorapatite composites was investigated. The sintering behaviour was investigated using X-ray diffraction, scanning electron microscopy and by analysis using ³¹P and ²⁷Al nuclear magnetic resonance. The composites sintering alumina additives have been tested in order to enhance their sinterability. When small amount of Al₂O₃ was added, densification of the tricalcium phosphate–26.52 wt % fluorapatite composites was markedly enhanced. The densification of the pure tricalcium phosphate–26.52 wt % fluorapatite composites was about 87 % , whereas it reached 91 % with 2.5 wt % Al₂O₃ at 1300 °C. High temperatures were not very efficient conditions. About 1400 °C, grain growth becomes important and induces an intragranular porosity which is responsible for decrease in density. The ³¹P and ²⁷Al MAS-NMR analysis of tricalcium phosphate–26.52 wt % fluorapatite composites sintered with Al₂O₃ additives reveals the presence of tetrahedral P and octahedral Al sites.