SiCf/Ti-6Al-4V复合材料界面反应动力学

SiC纤维增强Ti基复合材料（SiCf／Ti）容易发生界面反应，从而影响其力学性能。开展界面反应和动力学的研究，对于SiCdTi复合材料的制备和服役具有指导意义。采用扫描电镜、透射电镜和X射线衍射分析了SICf／Ti-6Al—4V复合材料的界面反应及其动力学，发现SiC纤维的C涂层与Ti-6Al—4V反应形成粗晶粒的和细晶粒的TiC，长期高温热处理使得界面反应加剧，TiC层加厚，当C涂层完全消耗后，界面反应层中除了TiC外，还出现了Ti3SiC2。研究表明，界面反应层的加厚受元素扩散控制，服从抛物线规律，求出的动力学参数Q为268．8kJ／mol，k为0．0057m/s1/2。

Kinetics of Interfacial Reaction in SiCf/Ti-6Al-4V Composites

The mechanical properties of the SiC fiber reinforced titanium matrix composites(SiCf/Ti) will degenerate due to the serious interfacial reaction that is easy to take place between SiC and titanium matrix. Therefore,It is very important to study the interfacial reaction and its kinetics for preparation and application of the composites. The interfacial reaction of Ti-6Al-4V composite reinforced with SiC fiber was investigated by means of Scanning Electron Microscope,Transmission Electron Microscope and X-ray diffraction. It was found that the interfacial reaction layers of TiC with fine grains and coarse grains,respectively,exist between Ti-6Al-4V and the C-coating of the SiC fiber in the composite. Some silicide,Ti3SiC2,was observed in the interfacial reaction zone of the composite when the C-coating is exhausted after long time heat treatment. The interfacial reaction is controlled bydiffusion which obeys parabola law and the kinetic parameters Q and k0 for the growth of the interfacial reaction zone are 268.8 kJ/mol and 0.005 7 m/s1/2,respectively.