陶瓷基复合材料的界面相容性研究

Study on Interface of Compatibility in Ceramic-Matrix Composites

有关陶瓷基复合材料(CMC)的界面问题已经得到广泛的重视。为了使材料达到一个很好的刚性,在纤维与基体之间保持尽量小的界面作用力对于陶瓷纤维增强Si—C—O复合材料是非常重要的。在纤维界面上涂层有利于减小它们之间相互作用,涂层处理后的Si—C—O复合材料的弯曲强度比一般无涂层的复合材料高5倍。在介质涂层、基体、以及涂层与纤维间的三相物质中避免化学反应的发生。目前,可利用化学相容性的原理对涂层纤维进行选择。

Critical issues of interface modifications in ceramic matrix composites have been investigated. Minimal interaction between the fiber and the matrix is essential to achieving good toughness in ceramic - fiber- reinforced Si - C - O composites. Introduction of a thin barrier coating on the fiber surface has been utilized to minimize such interaction. The flexural strength of a Si - C - O composite containing carbon - coated Nicalon fibers was found to be five times higher than that of the composite containing uncoated Nicalon fibers. Chemical reactions between the barrier coating and the matrix and those between the coating and the fiber must be avoided in such a three - phase material. A methodology for selecting candidate fiber coating materials by the use of chemical compatibility calculations is presented.