SiCf/Ti-60热稳定性研究

Thermal Stability of SiCf/Ti-60 Composites

摘要:

本文对采用磁控溅射先驱丝法制备的SiC_f/Ti-60复合材料进行不同温度下长时间热暴露实验,分析了热等静压态和热暴露态复合材料界面区结构稳定性及元素扩散规律。研究结果表明,界面反应层主要产物为TiC,纤维中C、Si元素和基体中Ti及其它合金元素进行互扩散；C元素扩散速率较快,在界面处和基体内形成TiC,基体中的TiC主要集中分布在α相晶界处。SiC_f/Ti-60复合材料反应层长大受扩散控制并遵循抛物线定律,界面反应层长大指数因子为2.27×10_-4 m/s_1/2,界面反应层长大激活能为118 kJ/mol。

Abstract:

Thermal stability of SiC_f/Ti-60 composites under thermal exposure at different temperature was studied. Interfacial reaction layer and element diffusion of SiC_f/Ti-60 composites after HIP and thermal exposure were also investigated. The results showed that the mainly product of reaction layer was TiC. The interdiffusion of C or Si in SiC fiber and Ti or other elements in matrix occurred. TiC was formed at the interface and in the matrix due to the high diffusion rate of C. TiC mainly existed on the grain boundaries of matrix. The growth behavior of SiC_f/Ti-60 composites reaction layer was influenced by diffusion and followed an Arrhenius law. The preexponential factor and the activation energy of SiC_f/Ti-60 composites were 2.27×10_-4 m/s_1/2 and 118 kJ/mol respectively.