热处理对碳化硅基复合材料结构与力学性能的影响

Effect of heat treatment on microstructure and mechanical properties of SiC matrix composites

摘要:

碳化硅纤维增强碳化硅复合材料（SiC/SiC）是极具前景的高温结构材料。本文通过先驱体浸渍裂解工艺（PIP）工艺制备了SiC/SiC复合材料。在惰性气氛下，1400~1800癈温度范围内对SiC/SiC复合材料进行热处理，用红外热像仪作为测温工具监测材料温度，研究了热处理温度和时间对SiC/SiC复合材料结构和力学性能的影响。结果表明，经1400癈热处理后复合材料基体结晶程度增加，整体力学性能提高；随热处理温度进一步升高，复合材料纤维受损，力学性能急剧下降。

Abstract:

Continuous SiC fibre reinforced SiC matrix composites (SiC/SiC) have been studied as materials for heat resistant and nuclear applications. Thermal stability is one of the key issues for SiC/SiC composites. In this study, 3D SiC/SiC composites are fabricated via the polymer impregnation and pyrolysis (PIP) process, and then heat treated at 1400~1800癈 in an inert atmosphere. The effect of heat treatment on microstructure and mechanical properties of the composites is investigated. The results indicate that the mechanical properties of the SiC/SiC composites are improved after heat treatment at 1400癈 mainly because the mechanical properties of the matrix are greatly improved due to crystallisation. With the increasing of heat treatment temperature, the properties of the composites are conversely decreased because of severe damage of the fibres and the matrix.