Dissimilar joining of AZ31B magnesium alloy and pure copper via thermo-compensated resistance spot welding. (December 2017)

• Record Type: Journal Article
• Authors: Shan, He; Zhang, Yu; Li, Yang; Luo, Zhen
• Is Part Of: Journal of manufacturing processes. Volume 30(2017)
• Page Start: 570
• Page End: 581
• Publication Date: 2017-12
• Subjects: Magnesium alloy -- Pure copper -- Dissimilar welding -- Resistance spot welding -- Thermo-compensated; Production management -- Data processing -- Periodicals; Manufacturing processes -- Periodicals; Procestechnologie; Productietechniek; Production -- Gestion -- Informatique -- Périodiques; Fabrication -- Périodiques; Manufacturing processes; Production management -- Data processing; Periodicals; 670.5
• DOI: 10.1016/j.jmapro.2017.10.022
• Languages: English
• ISSNs: 1526-6125

Abstract

Graphical abstract: Abstract: The feasibility of Mg/Cu dissimilar resistance spot welding (RSW) was investigated via a thermo-compensated process. Both physical factors and metallurgical properties of the welds affected the tensile shear properties of the joints. The mechanical properties of the Mg/Cu RSW joints were determined by the competitive relationship between these two factors. The increase in the nugget size with increasing Joule heat input improved the load-bearing ability of the joints. However, at the same time, the microstructure of the nugget transformed from an α-Mg solid solution fusion zone with a thin transition layer into an intermetallic compound (IMC)-enriching fusion zone with a thick transition layer. The mechanical properties of the joints deteriorated, owing to this transformation. All the Mg/Cu RSW samples fractured via interfacial failure (IF) mode and exhibited cleavage features. Although their ductility deteriorated owing to the IMCs, the Mg/Cu thermo-compensated RSW joints exhibited satisfactory tensile shear peak loads (maximum: 2626 N), which are comparable to that (2745 N) of Mg/Mg RSW joints. A reliable welding lobe suitable for industrial manufacture was obtained, when a welding time and a welding current of 100 ms–400 ms and 12 kA–20 kA, respectively, were recommended.