Microstructure and mechanical properties of dissimilar laser lap joint between CoCrFeMnNi-high entropy alloy and duplex stainless steel

Abstract A lap joint was formed between a CoCrFeMnNi-high entropy alloy (HEA) and duplex stainless steel (DSS) using laser beam welding. The microstructure morphology of the weld varied, with the upper section of the DSS side comprising a primary austenite phase and a secondary delta ferrite phase. An unmixed region that flowed from the DSS and characterized as ferrite was observed as the main metallurgical feature of the weld. The lower section was characterized by single austenite phase with large grains. Hardness fluctuations occurred within the weld, where the unmixed zone exhibited the highest hardness. The tensile shear strength of the joint was 470 MPa.