Si_3N_4陶瓷和ZrSiO_4复相陶瓷维氏压痕残余应力分布的扫描电子声学显微术观察

Observations of Scanning Electron Acoustic Micro scopy on Distributions of Residual Stress in Si3N4 Ceramics and ZrSiO4 Multiphase Ceramics

本文利用扫描电声显微术（ＳＥＡＭ）对Ｓｉ３Ｎ４陶瓷和３０ｖｏｌ％ＳｉＣ（ｗ）／ＺｒＳｉＯ４复相陶瓷中由维氏压痕引起的残余应力分布进行了电声显微像观察。比较了原位获得的二次电子像和电声像，表明电声像能够揭示样品的表面和亚表面的残余应力场分布。实验结果证实在陶瓷材料中由维氏压痕所引起的残余应力场是呈弹－塑性交替分布的区域，在维氏压痕的中心以及由压痕引起的裂纹对角线的端点是应力分布的集中区，同时显示ＳＥＡＭ技术在对陶瓷材料中残余应力场分布的研究中是一种有力的工具。

The distributions of residual stress arising from Vicker's indentation in Si3N4 and 30vol%SiC(w)/ZrSiO4 ceramics have been observed with scanning electron acoustic microscopy(SEAM). By comparing the secondary electron image and the electron acoustic image obtained in situ at the same time, it is shown that SEAM can be used to observe the variations of the residual stress distribution existing in different depth beneath the surface by changing the modulated frequency method. The experimental results prove that the distributions of the residual stress field are the elastic and plastic zone in turn. The central position of Vicker's indentation and the diagonal apexes of cracks are the stress concentration regions. It is shown that SEAM is a powerful tool for studying the distributions of the residual stress field in ceramics.