Temperature field and microstructure characterization of AA6061/H70 dissimilar thermo-compensated resistance spot welds having different joint configurations. (August 2017)

• Record Type: Journal Article
• Authors: Zhang, Yu; Shan, He; Luo, Zhen; Li, Yang; Bi, Jing; Guo, Jing; Gao, Feng
• Is Part Of: Journal of manufacturing processes. Volume 28:Part 1(2017)
• Page Start: 336
• Page End: 342
• Publication Date: 2017-08
• Subjects: Resistance spot welding -- Dissimilar metal joining -- Thermo-compensated method -- Finite element modeling; 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.2017.06.014
• Languages: English
• ISSNs: 1526-6125

Abstract

Graphical abstract: Highlights: AA6061 and H70 sheets are jointed by thermo-compensated resistance spot welding. The temperature field of two joint configuration are calculated by finite element modeling. Thermo-compensated method assist nugget formation in resistance spot welding by heat conduction. The two types of joints' microstructure feature are different. The tensile property of the joint is affect by its microstructure feature. Abstract: Two types of dissimilar AA6061/H70 thermo-compensated resistance-spot-welding joint configuration are designed. Thermal-electric coupled finite element models are built to reveal the temperature field of these two types of joint. An AISI 201 stainless-steel thermo-compensated sheet assists resistance spot welding through heat conduction. The nugget formation is mainly due to conductive heat from this cover sheet when the thermo-compensated sheet is set adjacent to the AA6061 workpiece (type A joint) and is driven by both Joule heat and conducted heat when the cover sheet is set adjacent to the H70 workpiece (type B joint). To ensure the nugget formation, the conducted heat portion requires a long welding time while the Joule heat portion requires a high welding current. The type B joint configuration has higher Cu and Zn contents in the fusion zone, which leads to a high intermetallic content in the Al-Cu-Zn ternary system existing in the nugget. Most type A joints thus have a higher peak load than type B joints in tensile shear tests.