Microstructure and Interfacial Reactions of Resistance Brazed Lap Joints between TC4 Titanium Alloy and 304 Stainless Steel Using Metal Powder Interlayers

Abstract

In the brazing joint between titanium alloy and stainless steel, a lot of Fe-Ti intermetallic compounds (IMCs) can be easily formed to make joints crack. A lap resistance brazing process with metal powder layers on both sides of the filler metal was used to solve this problem. The microstructure and metallurgical behavior of joints was studied through comparative experiments. The result showed that Nb, V and Cr powders and the solder reacted with the base material to form a new phase, which replaced the Ti-Fe brittle phase in the joint. At the same time, metal powder clusters hindered the diffusion of Ti and Fe elements and improved the distribution of new phases. The established atomic reaction model revealed the metallurgical behavior and formation mechanism of the joints. Therefore, the intervening position of the metal powder layer and the multi-reaction zone structure are the main reasons the shear strength of joints is improved.

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

“…Zhang et al used BAg45CuZn as the interlayer for RSW of TC4/304SS, and added three different adsorption layer structures of V/Cr [64], V + Nb/Cr [65,66] and V + Mo/Cr + Mo [67] between the substrate and the interlayer, respectively. The experimental results show that Fe-Cr, Fe-Nb, Ti-V, Mo-V, Mo-Cr and other phases with low brittleness can replace part of the original Fe-Ti phase with the intervention of Cr, V, Nb and Mo elements to effectively improve the strength of the joint.…”

“…The experimental results show that Fe-Cr, Fe-Nb, Ti-V, Mo-V, Mo-Cr and other phases with low brittleness can replace part of the original Fe-Ti phase with the intervention of Cr, V, Nb and Mo elements to effectively improve the strength of the joint. Zhang et al used BAg45CuZn as the interlayer for RSW of TC4/304SS, and added three different adsorption layer structures of V/Cr [64], V + Nb/Cr [65,66] and V + Mo/Cr + Mo [67] between the substrate and the interlayer, respectively. The experimental results show that Fe-Cr, Fe-Nb, Ti-V, Mo-V, Mo-Cr and other phases with low brittleness can replace part of the original Fe-Ti phase with the intervention of Cr, V, Nb and Mo elements to effectively improve the strength of the joint.…”

Friction spot brazing of stainless steel to titanium (grade 1) using aluminum foil

“…Common welding techniques used for joining Titanium to other base metals, such as TiG and MiG, use Argon gas to avoid this problem. These welding techniques are expensive and require complex tools [1,2]. Mechanical joining techniques such as friction brazing offers an alternative that is inexpensive, uses simpler tools and does not require the use of inert gases [3].…”