Publication

Abstract : AZ91D magnesium alloy plates of thickness 4 mm were successfully welded by CO2 laser welding. The heat input and hence the microstructural evolution were characterized by varying the laser power and welding speed. Moreover, microhardness, tensile strength, and elongation of the weldment were characterized. Hybrid models integrating the quadratic function and radial basis function were developed to correlate the laser welding process parameters with the properties of the laser-welded specimens. A comprehensive analysis of the influence of laser welding process parameters on properties is presented. The laser welding process parameters for maximizing the tensile strength, elongation, and microhardness of the weldment were determined using multi-objective optimization. The optimum laser welding parameters for AZ91D alloy were as follows: laser power of 2 kW and welding speed of 4.5 m/min. Inclusive analysis of the microstructural evolution and fracture mechanism of the laser-welded specimens is presented.