Weldability and mechanical properties of ultrasonic welded aluminum to nickel joints

• Ni/Al joints with and without interlayer were joined using ultrasonic spot welding.
• Effect of interlayer on the weldability and mechanical properties was studied.
• The joints with interlayer exhibited better weldability and mechanical properties.

Dissimilar aluminum to nickel joints with and without Al2219 particle interlayer were performed using ultrasonic welding technology. Interlayer was beneficial to improve the temperature of the weld interface, leading to the increase of weldability, by which sound aluminum to nickel joint was successfully obtained. Meanwhile an interface diffusion layer (~60 nm) was generated in the weld interface, and a significantly amount of welded regions were observed at the fracture surface. The maximum tensile shear load of joint with interlayer could reach 2.92 kN, which was 67.8% higher than that (1.74 kN) of joint without interlayer, meanwhile the welding time became shorter.