SiC_f/Ti60复合材料的热稳定性

Thermal Stability of SiC_f/Ti60 Composites

对采用磁控溅射先驱丝工艺制备的SiC_f/Ti60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,SiC纤维中C、Si元素和Ti60基体中Ti及其它合金元素进行互扩散;界面反应层主要产物为Ti C,Ti C层外侧环绕着一层硅化物;基体中的Ti C主要集中分布在α钛晶界处。SiC_f/Ti60复合材料反应层厚度长大受扩散控制并与温度的关系遵循阿伦尼乌斯规律,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 k J/mol。

Thermal stability of SiC_f/Ti60 composites under thermal exposure at different temperatures was studied.Interfacial reaction layer and element diffusion of SiC_f/Ti60 composites after hot isostatic pressing and thermal exposure were also investigated.The results show that the interdiffusion of C or Si in SiC fiber and Ti or other elements in the matrix occurs.The main product of reaction layer is Ti C at the interface and the outer layer of the Ti C layer is surrounded by(Ti,Zr)_xSi_y.Ti C mainly exists on the grain boundaries in the matrix.The thickness growth behavior of SiC_f/Ti60 composites reaction layer is influenced by diffusion and follows an Arrhenius law with temperature.The preexponential factor and the activation energy of SiC_f/Ti60 composites are 2.27×10^(-4) m/s^(1/2) and 118 k J/mol,respectively.