Interfacial Reaction of SiCf/Ti-43Al-9V Composite

Abstract:

SiC fiber reinforced g-TiAl (Ti-43Al-9V) matrix composite was fabricated by Fiber Coating Method (MCF) plus Vacuum Hot Pressing (VHP). The interfacial reaction products of the composites were identified and the reaction kinetics was studied. According to the analysis results by means of scanning electron microscope, energy dispersive spectrometer and X-ray diffractometer, the interfacial reaction products of TiC, Ti2AlC and Ti5Si3 were formed during the consolidation and the heat treatment of the composite. The reaction products are distributed in three layers of TiC/Ti2AlC/Ti5Si3+Ti2AlC(particle) from SiC fiber side to matrix side. The growth of the interfacial reaction products is controlled by diffusion and follows a rule of parabolic rate. The activation energy Q and the pre-exponential factor k0 of SiCf/Ti-43Al-9V composite are 190 kJ/mol and 2.5×10-5 m·s-1/2, respectively. It is confirmed that the thermal stability of the interface for the present g-TiAl matrix composite is better than that for other Ti alloy matrix composites.

Key words:SiC fiber; g-TiAl; composite; interfacial reaction; growth kinetics