Formation of interfacial microstructures of Mo-coating modified SiCf/Mo/Ti-6Al-4V composites

This paper addresses the role of Mo coating to modify the interface of SiC fiber reinforced Ti-6Al-4V composite (SiCf/Mo/Ti-6Al-4V). The formation of microstructure as well as the diffusion of elements in the interface of as-prepared and heat-treated SiCf/Mo/Ti-6Al-4V composites was investigated. The results show that the phases formed at the interfacial zone are: Mo coating vertical bar TiC vertical bar Mo+beta-Ti vertical bar beta-Ti vertical bar beta-Ti + alpha-Ti-strip, ordering from fiber to matrix. Mo coating can effectively hinder the diffusion of elements between the matrix and fiber to some extent, thus it can inhibit fiber/matrix interfacial reaction and protect the fiber from damage. It is believed that the beta-Ti layer formed around the interface can improve the formability of composites. Furthermore, it indicates that Mo coating exhibits excellent thermal stability bellow 700 degrees C according to the heat treatment of the composites at 700 degrees C for up to 200 h. Copyright (C) 2012 John Wiley & Sons, Ltd.