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

Abstract

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 R n ∼ 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.

Influence of Ni interlayer width on interfacial reactions and mechanical properties in laser welding/brazing of Al/Mg lap joint

“…In all cases, the joint failed at the Mg/Ni interface. More specifically, the fracture occurred at the interface between Mg 2 Ni and MgNi 2 , which was determined by XRD analysis on fracture surfaces in our pervious study [16]. Hence, the width of Mg-Ni IMCs dictated the joint fracture load.…”

“…To avoid these issues of solid-state welding, hybrid welding/brazing is a very promising joint technology [14, 15]. The authors, for the first time, proposed a laser welding/brazing technology for the joining of Al and Mg using a Ni interlayer as thermal and diffusion barriers [16]. The results have shown that the Ni played a dominant role in achieving successful joints: no joints were achieved without a Ni interlayer; after welding, specimens were separated without applying any force; however, by inserting a Ni interlayer, sound metallurgical bonding was obtained.…”

Suppression of liquid metal embrittlement in resistance spot welding of TRIP steel

“…During the RSW process, the coatings under the electrode indent melt and get squeezed outside the shoulder of the electrode indent. The formation of iron aluminides acts as a wetting barrier that helps the coating get completely squeezed out [29], leaving no zinc under the electrode indent. While only zinc was detected in the squeeze-out for zinc-coated samples in Figure 13, both zinc and aluminium were detected in the squeeze-out for aluminium interlayer samples in Figure 14.…”