摘要
利用ＸＲＤ、ＳＥＭ、ＥＰＭＡ和ＨＲＥＭ等测试技术系统地研究了Ｙ２Ｏ３－ＳｉＯ２添加剂对ＡｌＮ／ＳｉＣＷ复合材料力学性能及高温抗氧化性能的影响。结果表明：Ｙ２Ｏ３－ＳｉＯ２添加剂可有效地改善材料的力学性能，材料的氧化过程也是其热处理增强过程。添加剂组成接近其低共熔点时，材料随氧化时间的延长而得到增强增韧，且增幅最大，其最佳掺量为１０ｗｔ％。氧化处理改变了粒界玻璃相的相组成，玻璃相与ＡｌＮ颗粒发生作用，生成ＡｌＮ多形体２ＨδＳｉａｌｏｎ相，形成对材料有益的空间交错的结构。
The effect of Y 2O 3 SiO 2 additives on the mechanical properties and high temperature oxidation resistance of AlN/SiC W composites was studied through XRD, SEM, EPMA and HREM techniques in this paper.The results reveal that the mechanical properties of AlN/SiC W composites could be increased by using Y 2O 3 SiO 2 additives, and the oxidizing process of composites was just as the process of heat treatment.When the composition of Y 2O 3 and SiO 2 approached its eutectic point, the flexural strength and toughness of composites were enhanced with oxidizing time, and the increase amplitude was highest.The best content of additives is 10 wt%.The composition of glass phase in the grain boundary was varied in the course of oxidizing treatment, glass phase reacted with the surface composition of AlN to form the crossing structure of fibrous 2H δ Sialon and SiC whisker.
基金
国家863项目资助
关键词
添加剂
氧化钇
氮化铝陶瓷
复合材料
碳化硅
AlN/SiC W composites
Y 2O 3 SiO 2 additives
mechanical properties
high temperature oxidation resistance
