Effect of interlayer type on microstructure and mechanical property of impulse pressuring diffusion bonded joints in austenitic stainless steel to α titanium alloy

Abstract

Impulse pressuring diffusion bonding of an austenitic stainless steel to an α titanium alloy with three nickel interlayers in the form of nanopowder, nanoplating and foil was performed. The influence of interlayer type on microstructure and tensile strength of joints was investigated. The maximum strengths of the joints bonded using nanonickel powder, nanonickel plating and nickel foil were 212, 175 and 334 MPa respectively. Using nanonickel powder, pore and less tightness could weaken the joint strength. Using nanonickel plating, the reduced strength might be attributed to the plating layer with the low quality. Using nickel foil, fracture took place along Fe–Ni solid solution and Ni–Ti compound layers. A layered structure was present in the bonding region. No Fe–Ti intermetallic compounds formed in the joint, which indicates that the presence of nickel successfully prevents the interdiffusion of Fe and Ti.

Keywords:

• Impulse pressuring
• Diffusion bonding
• Stainless steel
• Titanium alloy
• Nickel interlayer

Acknowledgements

The authors gratefully acknowledge the Fundamental Research Funds for the Central Universities (project no. CDJZR12130047).