Diffusion bonding of SiC fibre reinforced Ti–6Al–4V alloy

Abstract

A continuous SiC fibre reinforced Ti–6Al–4V composite was diffusion bonded to itself. Incorporation of a Ti–6Al–4V interlayer and use of an etching treatment to smooth the faying surface improved the diffusion bondability of the composite. The bond strength increased with bonding time up to 10·8 ks under 10 MN m⁻² pressure at 1173 K, at which time, after reaching the maximum value of approximately 700 MN m⁻², the strength was saturated. Corresponding to this behaviour, the bonding between the interlayer and the composite matrix was completed after a bonding time of 10·8 ks. Bonding between the fibre and the interlayer was considered not to contribute to the joint strength on the basis of observation of the fracture surfaces. The bond strength therefore seems to be controlled by the bonding of the interlayer and the composite matrix. MST/1568