摘要
研究了ＳｉＣｗ／Ｙ－ＴＺＰ／Ａｌ２Ｏ３系复合陶瓷的显微结构及其力学性能，通过透射电镜拉伸试样中的裂纹扩展形态与组织变化，分析了晶须与ＺｒＯ２相变增韧机制．结果表明，陶瓷体内各相结合致密，分布较为均匀，其室温强度和断裂韧性值分别为１１００ＭＰａ和１１．９ＭＰａ·ｍ１／２．晶须拔出，裂纹偏转及ＺｒＯ２的应力诱导相变是该复合材料的主要增韧机制．增韧的关键是控制ｔ－ＺｒＯ２的稳定度，使得裂纹遇到晶须时，能使晶须—基体界面剥离，同时，裂纹周围的ｔ－ＺｒＯ２又易在裂纹扩展应力的诱导下相变．
Microstructure and mechanical properties of SiCw/Y-TZP/Al_2O_3 composites are studied. By examination of TEM though tensile sample, it has been found the changes of microstructure and morphology of crack propagation, and analyzed the whisker reinforcing and ZrO_2 transformation toughening mechanisms. The results show that all phases are connected compactly and distributed homogenously, the tensile strength and fracture toughness are 1100MPa and 11.9MPa·m1/2, respectively. The main reinforcing mechanism for this ceramic composite is pull-out of SiC whisker and crack deflection and t-m transformation of ZrO_2. The key to toughening is to control the stability of t-ZrO_2, when the crack meets the whisker, the interface between the whisker and matrix can be spalled off, meanwhile, the crack surrounded with t-ZrO_2 can incur transformation induced by crack propagating stress easily.
基金
山东省教育委员会资助
关键词
陶瓷复合材料
晶须
显微结构
增韧机理
Ceramic composites
Whiskers
Microstructure
/ Toughening mechanism
