Effects of welding parameters and surface pretreatments on resistance spot welding of AZ31B Mg alloy

The resistance spot weldability of AZ31B magnesium alloy using AC (alternating current) was investigated in this paper. The surfaces of sheet coupons were prepared by acetone cleaning (as-received) and some coupons were also cleaned with chromic acid (H2Cr2O7) after acetone cleaning (acid-cleaned). The surfaces of the as-received AZ31B sheets consisted of MgO, Mg(OH)2, and MgCO3. The extent and thickness of the surface oxide/reaction layer of …