SiC晶须-Al_2O_3复合陶瓷显微结构的电镜研究

MICROSTRUCTURE OF SiC WHISKER BREINFORCED Al_2O_3COMPOSITE CERAMIC

本文采用 X 射线衍射、扫描电镜、分析电子显微镜和高分辩电镜,研究了热压复合SiC-A1_2O_3陶瓷的相组成、晶须、晶须-基体界面间的显微结构。结果表明,复合陶瓷中的晶须为15R 型 SiC,基体为三方晶型的α-Al_2O_3。晶须内有大量的层错和孪晶;晶须-基体界面间存在一个过渡层,并有一定的取向关系。扫描电镜对样品断口的研究表明,存在晶须拔出和裂纹偏转两种增韧机制。

The phase composition,whisker microstructure and whisker-matrix inter-face of hot-pressing SiC-Al_2O_3 composite ceramic were studied by XRD,SEM,TEM andHREM.The results show that the whisker in the composite ceramics is 15R SiC and thematrix is triclinic system α-Al_2O_3.A large amount of stacking faults and twins exist inwhiskers.There is a transitional layer between interface of whisrer and matrix.The definiteorientation exists at interface between SiC whisker and Al_2O_3materix.The study of the frac-ture surface by SEM indicates that there are two reinforce mechanisms.