Effects of Interlayer on the Microstructure and Mechanical Properties of Resistance Spot Welded Titanium/Steel Joints: A Short Review

Abstract

In this paper, the influence of interlayer on titanium/steel dissimilar metal resistance spot welding is reviewed from the aspects of macroscopic characteristics, microstructure and interface bonding properties of the joint. Previous studies have demonstrated that TiC, FeTi and Fe2Ti intermetallic compounds with high brittleness are formed in the joint during titanium/steel welding, which reduces the strength of the welded joint. Researchers proposed different interlayer materials, including Cu, Ni, Nb, Ta, 60%Ni-Cu alloy and BAg45CuZn. Firstly, adding an interlayer can weaken the diffusion of Fe and Ti. Secondly, the interlayer elements can combine with Fe or Ti to form solid solutions or intermetallic compounds with lower brittleness than Fe–Ti compounds. Finally, Cu, Ni, Ag, etc. with excellent ductility can effectively decrease the generation of internal stress, which reduces the formation of defects to improve the strength of the joint.

Comparative Study of the Mechanical Properties and Fracture Mechanism of Ti-5111 Alloys with Three Typical Microstructures

“…Titanium alloys have a wide range of applications in aerospace and marine engineering due to their high specific strength, good toughness and excellent corrosion resistance [1][2][3][4]. The Ti-5111 alloy is a typical near-α titanium alloy developed as a cost-effective alternative to Ti-100 (Ti-5Al-2Nb-1Ta-0.8Mo), offering excellent weldability, moderate strength and affordability.…”