SiCf/Ti2AlNb复合材料的界面反应及热稳定性

界面反应层是影响SiC纤维(SiC_f)增强钛基复合材料力学性能的重要因素，本文研究了SiC_f/Ti₂AlNb复合材料在热等静压成型以及热暴露过程中的界面反应、界面元素分布规律和界面热稳定性.研究结果表明:SiC_f/Ti₂AlNb复合材料内部元素扩散形成的界面产物主要为TiC，在热暴露过程中出现了TiSi₂和NbSi₂相.SiC_f/Ti₂AlNb复合材料界面反应层的厚度长大符合Arrhenius定律，其界面反应层厚度长大速率随着热暴露温度的升高而增加.界面反应层长大激活能为24.27kJ/mol，界面层长大频率因子为2.80×10^-4 m/s^1/2.SiC_f/Ti₂AlNb复合材料界面在700℃及以下温度具备良好的热稳定性.

Interfacial Reaction and Thermal Stability of SiCf/Ti2AlNb Composites

The layer of interfacial reaction(IR)is an important influencing factor on mechanical properties of SiC fiber (SiC_f) reinforced titanium matrix composites. The interfacial reaction， element distribution at the interface and interfacial thermal stability of SiC_f/Ti₂AlNb composites during hot isostatic pressing and thermal exposure procedures are studied. The results show that the main IR product in SiC_f/Ti₂ AlNb composites is TiC， and the TiSi₂ and NbSi₂ phases are observed during the thermal exposure procedure. The thickness of IR layer in the SiC_f/Ti₂AlNb composite obeys the Arrhenius law， and the growth rate of IR layer increases with the thermal exposure temperature. The activation energy for the IR layer growth is 24.27kJ/mol， and the frequency factor is 2.80×10^-4 m/s^1/2. The interface of SiC_f/Ti₂AlNb composites shows good thermal stability at 700℃ and below.