Surface activation via irradiation damage treatment using low-energy protons to enhance pulsed-current-assisted diffusion bonding of Ti–6Al–4V alloy

Achieving a high-strength diffusion bonding joint at low temperatures is a challenge in the field of diffusion bonding. The irradiation damage treatment (IDT) of Ti–6Al–4V by low-energy proton irradiation significantly improved the nano-scale condition of the surface and enhanced the surface diffusion properties. In combination with the pulsed-current-assisted diffusion bonding (PCADB), the bonding ratio and joint strength were significantly improved at ultra-low temperatures of 500 °C and 550 °C. The combination of the surface activation effect of the IDT and the field-induced diffusion effect of the PCADB is expected to realize diffusion bonding of titanium alloys at ultra-low temperatures without side effects. • The surface is activated after the IDT using low-energy protons. • The IDT improved the PCADB efficiency significantly at ultra-low temperatures. • The enhanced efficiency achieved by this method is an atomic-level effect.