The effect of temperature on the chemistry and morphology of the interphase in an SCS6/Ti–6Al–4V metal matrix composite

Abstract

The changes in the chemistry and morphology within the interphase region of an SCS6/Ti–6A1–4V metal matrix composite upon exposing the samples to varying heat treatments have been studied using Auger electron spectroscopy, TEM and convergent beam diffraction techniques. These changes, such as the formation of small TiC particles at one interface and the narrowing of a protective pyrocarbon layer at another, induce fracture to occur at different places within the interphase upon heating. The reasons for this are explained. Evidence for a change in phase of a Ti_xSi_y(C) layer to the more thermodynamically stable Ti₅Si₃ is also given.