Effects of welding parameters on microstructures and mechanical properties of disk laser beam welded 2A14-T6 aluminum alloy joint

Disk laser beam welding technique is used to fabricate 2-mm 2A14-T6 aluminum alloy plates under different welding parameters. Effects of welding parameters on microstructures and mechanical properties of the weld are investigated. Grain size and porosity ratio in the disk laser welds firstly decrease, then increase with the increase of the heat input. Hardness at the fusion line and in fusion zone, tensile strength and elongation firstly increases, then decreases with the increasing heat input. When laser power is 2500 W, welding velocity is 2.0 m/min and heat input is 75 kJ/m, the finest microstructures, the minimum porosity ratio, the highest hardness and the maximum tensile strength are obtained. The fracture type in all samples is defined as a ductile fracture, and the maximum tensile strength reaches up to 261.7 MPa, about 61.2% of that of the base metal.