Effect of the Bonding Temperature on the Bonding Interface in the Press Bonding of Ti-17 Alloy

The press bonding experiments of Ti-17 alloy were conducted at the bonding temperatures ranging from 730°C to 880°C, a bonding pressure of 20 MPa and a bonding time of 15 min. The results show that the plastic deformation is a main bonding mechanism in the press bonding of Ti-17 alloy. With an increase in bonding temperature, the plastic deformation enhances and voids in the bonding interface disappear gradually. The grain boundary migration and grain growth spanning the bonding interface start to activate, which is of benefit to obtaining a sound bond. The failure mode of bonding interface changes from a brittle fracture to a ductile fracture. However, a higher bonding temperature will induce grain coarsening which result in strength decreasing. The SEM of lap shear fracture surfaces indicates that a bond with superior strength can be obtained at a bonding temperature of 860°C.