Al2O3-ZrO2复相陶瓷压缩变形织构及其对组织性能的影响

采用真空热压烧结法制备了3Y-ZrO2/Al2O3细晶复相陶瓷,对其致密块料进行了高温压缩变形,分析了材料变形前后的显微组织和力学性能.结果显示,XRD及X射线极图显示压缩变形后的陶瓷材料具有明显的织构特征,最大织构强度达到7.3.织构化陶瓷的弯曲强度,断裂韧性和维氏硬度值随应变量的增加呈逐步增大的趋势,最大值分别为933.8MPa,10.4MPa·m1/2和20.4GPa.当真应变很高(1.72)时,力学性能呈现一定幅度的降低趋势.分析表明织构化可以大幅提高材料的力学性能,同时极高变形量下形成的粗化晶粒和大尺寸空洞又导致力学性能的降低.

Microstructure and Mechanical Properties of Textured Alumina-Zirconia Composites Prepared by Compressive Deformation

3Y-ZrO₂/Al₂O₃ fine-grained composite compacts were prepared by vacuum hot pressed sintering and then compressed at elevated temperatures. The microstructure and mechanical properties of the composites before and after deformation were investigated. Results show that the apparent textured microstructure is observed in the deformed ceramics through XRD and X-ray pole figure measurement. The maximum degree of texture reaches 7.3 times random. As the true strain increases, bending strength, fracture toughness and Vickers hardness increase up to 933.8MPa, 10.4MPa·m ^1/2 and 20.4GPa, respectively. When the true strain increases to 1.72, the mechanical properties decrease to some extent. It is concluded that the texture effectively improves the mechanical properties of the composite ceramic, while the coarsening grains and big cavities formed under extremely high strain induce the decrease of mechanical properties.