Use of zinc powder on Resistance Spot Welding on Mild Steel and aluminium

Abstract

This study aims to determine mechanical properties of dissimilar metal resistance spot welding using zinc powder as an intermediate between 4000 series aluminium 1.2 mm thick with mild steel AISI 1008 thick 0.9 mm. The experiment was conducted on current parameters 7000 A, 8000 A, 9000 A, zinc powder mesh 200, and holding time 5 s. Tensile test showed that an optimal value on joining strength is at a current variation of 9000 A time 0.5 s of 1586.46 N. Additionally, Hardness testing in the weld metal area yields an optimal value at similar parameters as 232 HVN for aluminium and 210 HVN for Mild Steel. Based on Macro photo test results show that the current affects the width of the weld metal (nugget), the greater the current the wider the weld metal. Meanwhile, based on micro photos, there is a change of grain size on aluminium and mild steel welding.