A study on the mechanical and electrical performance of Al/Cu laser multi-seam welded joints

Abstract

Aluminum alloy and copper used in lithium-ion batteries have low absorption and high reflectivity, so it is difficult to obtain stable joint strength when laser welding is applied. In order to overcome problems, this study has applied multi-seam weld to increase joint area of welded joints. An AA1050-H18 and C11020P sheets with a thickness of 0.5 mm were welded by 2 kW fiber laser welding. Effect of the welding parameters of pitch (0, 1, 4, 8 mm) on weldability in welded joints has been investigated. As the pitch of multi-seam increased, the tensile-shear load tended to increase. The maximum tensile-shear load in the multi-seam weld of pitch 8 mm was 1.25 kN, which was about 108% compared to the single-weld seam 0.6 kN. In addition, the minimum electrical resistance was 77 μΩ at the pitch of 8 mm, which decreased by approximately 49% compared to 115 μΩ of single seam welding. It is thought because resistance reduction caused by be changed from serial to parallel in multi-seam welding.