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℃. The optimum values of densificatio...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℃. 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℃ 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.展开更多
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℃. 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℃ 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.
