Friction stir spot welding (FSSW) is a variation of linear Friction Stir Welding (FSW), which was invented to compete with resistance spot welding (RSW) and riveting of lightweight alloys in the au...

Advances in friction stir spot welding

The study of dissimilar metals’ welding is an important issue due to their increasing applications in many industrial fields. Welding of dissimilar metals is challenging because of the formation of large residual stress and brittle intermetallic compounds (IMCs). In order to solve this problem, intermediate interlayers were used to eliminate or inhibit the formation of brittle intermetallic reaction layers in many welding techniques, such as diffusion bonding, laser welding, electron beam welding, and other welding techniques. The aim of this paper is to review the recent progress of dissimilar metals’ welding methods and mechanisms with interlayer to offer a basis for the following research. The work discussed several criteria for the selection of interlayer, such as physical properties, metallurgical compatibility, mode, and thickness of the interlayer. Then, formation enthalpy, Gibbs energy of formation (ΔG), and brittleness of the IMCs, as well as welding parameters, were also discussed. Simultaneously, the present work had proposed a design guideline for the selection of interlayer in dissimilar metals’ welding to acquire a welded joint with good quality.

A review on dissimilar metals’ welding methods and mechanisms with interlayer

Brazing is a 5000-year-old joining process which still meets advanced joining challenges today. In brazing, components are joined by heating above the melting point of a filler metal placed between...

https://tandfonline.com/doi/pdf/10.1080/09506608.2019.1613311

Brazing filler metals

Dissimilar MIG-CMT weld-brazing of aluminium to steel: A review

A thermoplastic ABS and an aluminium alloy 6061-T6 were joined using friction lap welding (FLW). The joint characteristics were evaluated to investigate the effects of 6061-T6 surface and the weldi...

Direct joining of thermoplastic ABS to aluminium alloy 6061-T6 using friction lap welding

This work offers an analysis of the wetting behaviour of the Zn–xAl filler metal spreading on the stainless steel. Effects of Al content on wetting kinetics and microstructures of the re-solidified filler metal were studied in this important system of dissimilar substrates. Experimental results have confirmed that the wetting of Zn–xAl filler metal on stainless steel features the trend of triple-line kinetics. In the main spreading phase, the spreading radius and time can be correlated with a power law of Rn ∼ t, n = ∼0.4. The content of Al in the filler metal has a minimal effect on the value of n for the investigated range of Al concentrations. However, the spreading area of the filler metal after re-solidification decreases with an increase of the content of Al. Moreover, the thickness of the Fe–Al intermetallic layer at the cross-section increases with an increasing Al content.

Wetting behaviour of Zn–Al filler metal on a stainless steel substrate

This work offers an analysis of the microstructure and the growth rate of an intermetallic compound within the aged AA 6061 aluminum alloy-304 stainless steel joint brazed with Zn-15Al and Zn-15Al-0.2Zr filler metals. The effect of zirconium addition on mechanical integrity of the brazed joint was studied. The experimental results confirm that the thickness of the Fe-Al intermetallic layer formed at the brazed seam/stainless steel interface increases with the increase of the aging time. Furthermore, it is established that the growth rate of the intermetallic layer for the Zn-15Al-0.2Zr brazed joint was lower than that for Zn-15Al. The results also indicate that the shear strength of both Zn-15Al and Zn-15Al-0.2Zr brazed joints decreases monotonously during aging. The value of the strength after aging lasting for 800 h for Zn-15Al and Zn-15Al-0.2Zr has decreased by 20 and 17%, respectively. The fracture of joints occurred at the interface between the brazed seam and the Fe4Al13 intermetallic layer. The morphology of the surfaces exhibits a cleavage fracture.

Jinlong Yang

Papers

Wetting behaviour of Zn–Al filler metal on a stainless steel substrate

An Impact of Zirconium Doping of Zn-Al Braze on the Aluminum-Stainless Steel Joints Integrity During Aging