原位Al2O3片晶/Ce-TZP和SrO·6Al2O3棒晶/Ce-TZP复合材料的制备与显微结构

通过在Ce-TZP基体中加入AlOOH及矿化剂TiO₂或反应剂SrCO₃制备了原位Al₂O₃片晶/Ce-TZP复合材料和原位SrO·6Al₂O₃棒晶/Ce-TZP复合材料。在烧结过程中TiO₂促进Al₂O₃晶粒发生显著的各向异性生长原位生成的片晶、Al₂O₃与SrCO₃发生反应,原位生成的高度各向异性的棒晶,它们在基体中分布均匀,具有较大的纵横比。烧结温度对片晶/棒晶的大小和含量有明显影响。通过在基体中原位形成片晶或棒晶,材料的力学性能有明显的改善。

PREPARATION AND MICROSTRUCTURE OF IN SITU REINFORCED Ce-TZP MATRIX COMPOSITES

In situ reinforcement of ceramic matrix can be achieved by the elongated grains or platelets in situ formed in matrix during sintering through the mechanisms of crack bridging, crack deflection, elongated grain/platelet pullout, etc. In this work, in situ Al2O3 platelet/Ce-TZP composites and in situ SrO·6Al2O3 rod-like grain/Ce-TZP composites were prepared by adding AlOOH together with the mineralizer of TiO2 or the reactant of SrCO3 to Ce-TZP matrix. The microstructure of the composites was observed by SEM, and the density and mechanical properties of the composites were measured. The results indicated that TiO2 markedly promoted the anisotropic grain growth of Al2O3 and SrCO3 reacted with Al2O3, forming Al2O3 platelets and anisotropic SrO·6Al2O3 rod-like grains respectively. The in situ Al2O3 platelets and SrO·6Al2O3 rod-like grains were well-distributed in the matrix with a larger aspect ratio. Sintering temperature obviously affected the grain size and the content of Al2O3 platelet and SrO·6Al2O3 rod-like grain. The mechanical properties of the composites were improved by in situ introduction of Al2O3 platelets and SrO·6Al2O3 rod-like grains.