Investigation of Interface in SiC Fiber Reinforced TC17 Titanium Alloy Matrix Composites

Abstract

The investigations were focused on the thermochemical and mechanical properties for interface in continuous SiC fiber reinforced TC17 titanium alloy (nominal composition wt.% is Ti-5Al-2Sn-2Zr-4Mo-4Cr) matrix composites (SiCf/Ti). Scanning electron microscope (SEM), transmission electron microscopy (TEM), and electron probe microanalyzer (EPMA) were applied to observe and analyze the interface reaction product at different heat treatment temperatures. In addition, the reaction rate as well as the relationship between the thickness of reaction layer and time was researched. The interfacial strength at different consolidation temperatures was obtained by means of push-out test, while erosion method was employed to measure the residual stress of composites under different consolidation parameters. The results demonstrate that the thickness of interface reaction layer and heat exposure time is accord with the relationship x=kt1/2+x0, and the interface strength is correlated with the thickness of interface reaction layer, which increases with the intensity of interface reaction. Through the comparison, we find that the inner residual stress of the sample consolidated at 940 °C is higher than that of 920 °C.