ABSTRACT
Resistance spot welds with three aluminium to steel sheet thickness ratios were welded using electrodes featuring a plurality of rings and multiple solidification weld schedules. The average shear strength of the intermetallic layer was measured directly using a mini-shear test while the shear stress at the interface was calculated using finite element analysis. The results demonstrated that the fracture modes changed from interfacial fracture to fracture in aluminium when the steel thickness increased or the aluminium thickness was thinner than the steel. Therefore, interfacial fracture can be minimised by decreasing aluminium to steel thickness ratio. This was due to a reduced shear to tensile stress ratio and a lower shear stress than the shear strength at the weld faying interface.
Acknowledgements
The authors are grateful for the technical assistance provided by Jie Liang, Catherine Bibby, Pei Liu, Mark Gesing and Ruby Zhang in various aspects of the experimental and modelling work reported here. The authors are also grateful to Chad Clark (Fusion Welding Solutions) for his welding assistance and Robert Herbon for metallographic assistance. Liting Shi greatly thanks her supervisor Professor Xu Chen for support.
Disclosure statement
No potential conflict of interest was reported by the authors.
ORCID
Babak Shalchi Amirkhiz http://orcid.org/0000-0002-6756-0278