Abstract
AZ31B magnesium alloy/AA6061 aluminium alloy welded structures have been widely used in the lightweight design of automobile bodies. To improve the joint strength, the ultrasonic spot welding (USW) solid state connection method is used in this paper. The results show that at a welding energy of 1540 J, there is evidence of melting in the weld joint. As the welding energy increases, the intermetallic compounds (IMCs) grow rapidly and form a reaction layer approximately 17 μm thick. The IMCs are mainly composed of the γ-Mg17Al12+β-Mg2Al3 phase, where the β-Mg2Al3 phase hardness is as high as 6.5 GPa and shows a typical pop-in phenomenon and the average hardness of the γ-Mg17Al12 cubic structure phase is 3.4 GPa. When the welding energy reaches 1540 J, the β phase rapidly grows, and the joint performance decreases rapidly. The fracture morphology indicates a cleavage fracture and is accompanied by a large number of secondary cracks.
Highlights
In many engineering applications, multiple material structures are more efficient and perform better than the same structure produced from a single material
Researchers have made a lot of efforts in dissimilar welding from the optimization of process parameters, adding filler materials (It can reduce the intermetallic compounds (IMCs) thickness, minimize the defects and increase the strength.) and establishing an IMC growth model for the Ultrasonic spot welding (USW) process of aluminium alloy/ magnesium alloy dissimilar metals (It can effectively predict the thickness of IMC generated in the welding interface under different process parameters)[16,17,18]
It can be seen from these research papers that the generated IMCs deteriorate the joint performance and the failure is mainly determined by the distribution and thickness of the IMCs, but when the size is controlled within a certain range, the generated IMCs can improve the joint performance
Summary
Multiple material structures are more efficient and perform better than the same structure produced from a single material. Researchers have made a lot of efforts in dissimilar welding from the optimization of process parameters, adding filler materials (It can reduce the IMC thickness, minimize the defects and increase the strength.) and establishing an IMC growth model for the USW process of aluminium alloy/ magnesium alloy dissimilar metals (It can effectively predict the thickness of IMC generated in the welding interface under different process parameters)[16,17,18] It can be seen from these research papers that the generated IMCs deteriorate the joint performance and the failure is mainly determined by the distribution and thickness of the IMCs, but when the size is controlled within a certain range, the generated IMCs can improve the joint performance. This study has broad application prospects for enriching the theoretical basis of ultrasonic welding of dissimilar metals
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
