Effect of Mg interlayer on the microstructure and mechanical performance of resistance rivet welded 2 mm Al and ultra-high strength steel

Luyao Kong; Sizhe Niu; Ming Lou; Zixuan Chen; Yunwu Ma; Yongbing Li; Haiyang Lei

Journal of Materials Research and Technology (Jan 2025)

Effect of Mg interlayer on the microstructure and mechanical performance of resistance rivet welded 2 mm Al and ultra-high strength steel

Luyao Kong,
Sizhe Niu,
Ming Lou,
Zixuan Chen,
Yunwu Ma,
Yongbing Li,
Haiyang Lei

Affiliations

Luyao Kong: School of Mechanical Engineering, Shandong University of Technology, Zibo, 255000, PR China
Sizhe Niu: School of Mechanical Engineering, Shandong University of Technology, Zibo, 255000, PR China; Corresponding author.
Ming Lou: Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, PR China; State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, 200240, PR China; Corresponding author. Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, PR China.
Zixuan Chen: Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, PR China; State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, 200240, PR China
Yunwu Ma: Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, PR China; State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, 200240, PR China
Yongbing Li: Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, PR China; State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, 200240, PR China
Haiyang Lei: Shanghai Smart Fusion Industrial Equipment Co., LTD, Shanghai, 201311, PR China

Journal volume & issue: Vol. 34
pp. 691 – 702

Abstract

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Resistance rivet welding (RRW) using semi-tubular rivet was employed to join 2 mm thick AA6061 T6 Al alloy and ultra-high strength steel (UHSS). The influence of a Mg interlayer on the evolution of joint microstructure, mechanical performance and fracture characteristics were thoroughly investigated. The presence of Mg interlayer has negligible impact on the mixed nugget size; however, it significantly alters the joint microstructure. The nugget microstructure is composed of the mixed ferrite and martensite, and the full martensite structure for the RRW joints without and with a Mg interlayer, respectively. The Mg interlayer utilized in RRW plays a significant role in facilitating the formation of martensite. The solidification mechanism of the mixed nugget without the Mg interlayer is governed by the competition between ferrite and austenite stabilized elements. In contrast, for the mixed nugget with the Mg interlayer, the solidification mechanism is primarily influenced by the austenite stabilized elements. Tensile-shear tests reveal that joints with an Mg interlayer predominantly exhibit a button pull-out fracture (BPF) mode, while joints without the Mg interlayer demonstrate the mixed failure modes, including interfacial fracture and BPF. Furthermore, the influence factors including the mixed nugget size, nugget microstructure and load-bearing capacity of the rivet head were analyzed.

Published in Journal of Materials Research and Technology

ISSN: 2238-7854 (Print); 2214-0697 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Technology: Mining engineering. Metallurgy
Website: https://www.journals.elsevier.com/journal-of-materials-research-and-technology/

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