Fatigue behaviour of dissimilar Al 5052 and Mg AZ31 resistance spot welds with Sn‐coated steel interlayer

Abstract

The fatigue property of dissimilar spot welds between an aluminium alloy (AA5052) and a magnesium alloy (AZ31) was studied in this research. The AA5052 and AZ31 coupons were resistance spot welded together by using an interlayer of Sn‐coated steel between the two coupons. The fatigue test results revealed that the Mg/Al joints had the same level of fatigue strength as Mg/Mg resistance spot welds. It was found that within the life range of Nf < 105 cycles, Mg/Al welds degraded faster than Mg/Mg joints. This was attributed to the larger bending moment on the plane of fatigue failure in the Mg/Al welds. Three failure modes were observed under different cyclic loading regimes: Al/steel interfacial failure, Mg coupon failure and Al coupon failure. Fatigue fracture surface of Mg/Al welds consisted of two distinct regions: crack propagation region with brittle morphology and final rupture with ductile morphology.

Advances in additive manufacturing of metal-based functionally graded materials

“…Ferritic to austenitic steel welds are well understood and documented; more challenging welds such as Al-Mg are still subject to study and generally considered not to be weldable [41], with the lack of solubility between Al and Mg leading to the formation of Al 3 Mg 2 and Al 12 Mg 17 phases which promote cracking. Several different welding techniques have been deployed on these dissimilar welds such as resistance spot welding (RSW) [42], metal inert gas (MIG) welding [43], laser and its hybrid welding [44,45], and friction stir welding (FSW) [46,47]. Interlayer materials, such as Ni, are still required to join the Al-Mg materials reliably.…”

Proposal of Evaluation Method for Crack Propagation Behaviors of Second-Generation Acrylic Adhesives under Mode I Static Loading

“…The automotive industry involves lightweight and high-strength structural designs that consider environmental issues [1][2][3]. Conventional welding technologies have been extended to dissimilar materials [4,5]. Adhesive bonding is applied based on features, such as bonding for dissimilar materials, vibration resistance, and high work efficiency [6,7].…”

Fatigue strength of austempered ductile iron-to-steel dissimilar arc-welded joints

“…In the technical literature, many papers have been dedicated to explore different welding techniques for joining dissimilar materials: the most widely adopted is the friction welding [2][3][4][5][6][7][8][9], together with arc welding [10][11][12][13][14][15][16] and laser welding [17,18], but also other techniques are employed, such as resistance spot welding [19,20] and magnetic pulse welding [21]. In the context of arc welding, joining austempered ductile iron (ADI) to dissimilar structural steel allows the mechanical response of structural components to be improved, combining weight reduction and net-to-shape geometry at the same time.…”

“…However, International Standards and Recommendations [22][23][24] provide fatigue strength categories based on the nominal stress approach only for homogeneous welded joints, made of structural steels or aluminium alloys, and not for dissimilar joints. Several papers in the recent literature have addressed the analysis of the fatigue behaviour of dissimilar joints made of different grades of structural steels [2,3,[10][11][12][13][14][15]17], different series of aluminium alloys [4], a steel and an aluminium alloy [6][7][8][9] or other metallic materials welded together [5,19]. However, to the best of authors' knowledge, a quantitative analysis of the fatigue behaviour of dissimilar ADI-to-steel welded joints is lacking in the technical litera t ure and in all I nterna tio nal Stan dard s an d Recommendations [22,24].…”