Effect of Titania Additive on Structural and Mechanical Properties of Alumina-Fluorapatite Composites

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• 作者：Awatef Guidara ; Kamel Chaari ; ^{kamel.chaari@enis.rnu.tn} ; Jamel Bouaziz
• 关键词：Sintering ; Fluorapatite ; Alumina ; Titania ; Composites ; Biomedical applications
• 刊名：Journal of Materials Science & Technology
• 出版年：2012
• 出版时间：December, 2012
• 年：2012
• 卷：28
• 期：12
• 页码：1130-1136
• 全文大小：1907 K

文摘

Mechanical properties of alumina-fluorapatite composites with different titania additive amounts (0, 0.5, 1, 1.4, 2, 3, 4 and 5 wt % ) have been investigated between 1200 and 1600 ¡ãC. The optimum values of densification and mechanical properties of composites have been reached with 1.4 wt % of titania after the sintering process at 1500 ¡ãC for 1 h. Thus, the rupture strength of alumina-26.52 wt % Fap-1.4 wt % TiO₂ reaches 75 MPa. At higher temperature and beyond 1.4 wt % TiO₂, the densification and mechanical properties were hindered by the formation of both intergranular porosity and secondary phase. X-ray diffraction (XRD) analysis of alumina-Fap-TiO₂ composites shows the formation of aluminium titanate (Al₂O₃-TiO₂: Al₂TiO₅). The ²⁷Al magic angle scanning nuclear magnetic resonance analysis of Al₂O₃-Fap-TiO₂ composites reveals the presence of octahedral and pentahedral aluminium and novel environment relative to tetrahedral aluminium sites.