Diffusion bonding of SiC/Ti–6Al–4V composite to Ti–6Al–4V alloy and fracture behaviour of joint

Abstract

AbstractContinuous SiC fibre reinforced Ti–6Al–4V composites were diffusion bonded to Ti–6Al–4V alloy. Bondability and the fracture mechanism of the joint were investigated. The joint strength increased with bonding time, and was a maximum at 850 MN m−2 for Vf=30% composite and 650 MN m−2 for Vf=45% composite. The bonding was completed sooner for Vf=30% composite than for Vf=45% composite. In Vf=30% composite, the maximum joint strength was about 85% of the tensile strength of Ti–6Al–4V. The void ratio at the interface between matrix and Ti–6Al–4V alloy decreased as bonding time increased. The joint strength was controlled by the bonding between the composite matrix and the Ti–6Al–4V alloy. The maximum joint strength was 100–150–MN–m−2 higher than the strength simply calculated from the area fraction of the bonded matrix/Ti–6Al–4V interface. Fibres were debonded from the matrix and the defects were produced around fibres, so the state of stress at the bond interface is triaxial owing to the defects and/or...