Comparison of continuous and pulsed wave lasers in keyhole welding of stainless-steel to aluminium

Abstract A continuous wave (CW) and a nanosecond pulsed (PW) lasers were used to join 1-mm thick sheets of SS304L (SS) austenitic stainless-steel AA5251 (Al) aluminium alloy in an overlap joint configuration. The weld shape (penetration depth width), intermetallic compounds concentration, quality (cracking porosity) mechanical strength correlated with the process energy compared between each laser temporal mode. Successful CW joints produced SS sheet on top Al, but opposite configuration revealed be impossible for range parameters tested. PW successful Al SS, all cracked at interface when was used. tests showed that even though it is possible achieve higher tensile shear load welds due larger bonding area, almost 5 × similar applied energy.