Investigation on the influence of SiCf/TC17 composites preparation method on growth kinetics of interfacial reactive layer

Abstract

Continuous SiC fiber reinforced titanium matrix composite（SiCf/Ti composite）has good specific strength and comprehensive mechanical properties, it is a lightweight high temperature structural material that attracts much attention in the new generation of equipment development. SiCf/Ti composites can be prepared by the methods of foil fiber foil（FFF）and matrix coating fiber（MCF）. In order to compare the effects of the two methods on the growth of interfacial reaction, SiCf/TC17 composites were prepared by FFF and MCF respectively. By study the interfacial reaction layer thickness of composites prepared by the two processes after thermal exposure at the temperature from 800℃ to 900 ℃, the microstructure and the thickness of interfacial layer were analyzed by scanning electron microscope, further the interfacial reaction rate at high temperature was obtained, and the interfacial reaction kinetic parameters of different materials were attained. The results showed that the interfacial reaction rate of SiCf/TC17 composite prepared by MCF method was higher than that of the composites prepared by FFF method at the same temperature. The interfacial reaction rate factor k0 is 4.942×10−3 m/s1/2 and 8.149×10−3 m/s1/2 for the composites prepared by MCF and FFF method, respectively. Additionally, the reaction activation energy Q is 276.3 kJ/mol and 291.7 kJ/mol for those, respectively. This is because the titanium alloy matrix prepared by MCF method has smaller phase structure and higher element diffusion rate at high temperature. Therefore, the composite prepared by MCF has lower reaction activation energy at high temperature.

Keywords

• sicf/ti composite
• foil fiber foil
• matrix coating fiber
• reaction kinetic