摘要
本文研究了高温等静压（HIP）后处理工艺对液相烧结SiC陶瓷的显微结构及力学性能的影响．实验表明，HIP后处理的效果随烧结助剂的不同及液相烧结温度的变化而改变．Ar气氛条件下的HIP后处理可以提高液相烧结SiC的密度，减少或消除内部气孔等结构缺陷，但不引起晶粒的长大．N_2条件下的HIP后处理除了具有Ar－HIP后处理的优点外，由于表面SiC与N_2之间的反应生成的Si_3N_4可以有效地改善表面状态，从而达到表面改性，提高SiC陶瓷的力学性能．结构分析表明，经N_2-HIP后处理，表面氮化层中晶粒细小，结构致密．同时，HIP后处理的效果还受液相烧结SiC陶瓷显微结构的影响，当液相烧结SiC的烧结温度较低，晶粒较细时，经HIP后处理，尤其是N_2-HIP后处理，强度和韧性均有较大幅度的提高．
The microstructure and mechanical properties of liquid phase sintered SiC followed by posthot isostatic pressing (HIP) were studied. It is indicated that the effect of post-HIP treatment is changed with the variation of sintering aids and temperature of liqllid phase sintering. After Ar-HIP treatment, the density of SiC is increased and the inside pores are diminished, but graingrowth is depressed. Besides the advantages of the Ar-HIP, N_2-HIP can modify the surface statebecause of the reaction between SiC and N_2 so that the mechanical properties are improved.Microstructure analysis has shown that after N_2-HIP treatment, grain size is decreased and thedensity is increased. Meanwhile, the results of post-HIP treatment are highly affected by themicrostructure of the liquid phase sintered SiC. When the sintering temperature is relatively lowerand the grain size is smaller, after post-HIP treatment, esp. N_2-HIP treatment, bending strengthand fracture toughness of the liquid phase sintered SiC are improved greatly.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
1997年第6期791-796,共6页
Journal of Inorganic Materials
关键词
液相烧结
高温
等静压
后处理
结构
碳化硅陶瓷
liquid phase sintering, SiC, post-hot isostatic pressing, microstructure, properties
