Optimisation of Process Parameters for Resistance Spot Welding of AA7075-T6 Aluminium Alloy

The lightweight structural design has emerged as a prominent research priority in the automotive industry and aerospace sectors due to its capacity for reducing overall vehicle weight and energy consumption while ensuring structural strength. This work presented the optimal welding process parameters for AA7075-T6 aluminium alloy,which were determined through orthogonal experiments. Tensile shear tests,metallographic observations,and microhardness tests were performed on the joints,followed by numerical simulations of the optimal parameter combinations to investigate the impact of welding process parameters on joint quality. The results demonstrate that spot welded joints exhibit superior integrated mechanical properties when subjected to a welding time of 60 ms,a welding current of 17 kA,and an electrode pressure of 0. 22 MPa. It was observed that the order of influence exerted by welding parameters on mechanical properties of resistance spot weld joints is as follows:welding time > welding current > electrode pressure. The nugget size obtained from numerical simulation aligns with experimental findings. Spattering and the shrinkage defects occur within the nugget during the welding process,leading to compromised mechanical properties in joints and interfacial fracture failure modes. Due to alterations in microstructure within joints during the welding process,microhardness exhibits a ‘W’shape. © 2024 Cailiao Daobaoshe/ Materials Review. All rights reserved.