SiC_f/SiC复合材料氮化硼(BN)界面层及其复合界面层研究进展

Research progress of BN interphase and its multilayers in SiC_f/SiC composites

SiC_f/SiC复合材料由SiC纤维、SiC基体和界面层组成。界面层可以传递载荷和偏转裂纹,同时防止SiC纤维受到材料制备和使用过程中的化学侵蚀,对于调节SiC_f/SiC复合材料的性能具有非常重要的作用。本文综述了氮化硼界面层的晶体结构、复合界面层的种类,介绍了化学气相渗透法制备氮化硼(boron nitride,BN)及其复合界面层的工艺条件,总结了先驱体气体比例、载气、沉积压力及温度等工艺条件对界面层沉积速率、微观形貌结构的影响。选择合适的工艺条件,制备理想结构的BN及其复合界面层,将是SiC_f/SiC复合材料界面层研究领域的重点和难点。

SiCf/SiC composites are consisted of SiC fibers,SiC matrix and interphase.The interphase can transfer stresses from matrix to SiC fibers and deflects microcracks,at the same time,it protects SiC fibers from chemical erosion during the preparation and use of materials,which plays a very important role in regulating the properties of SiCf/SiC composites.In this paper,the effects of precursor gas ratio,carrier gas,deposition pressure,temperature on the deposition rate and microstructure of interphase during the chemical vapor infiltration(CVI)process are summarized.It will be the key and difficult point in the research of SiCf/SiC composite interphase to select appropriate process conditions and prepare BN and its composite multilayer with ideal structure.