Prediction and optimization of pulsed current tungsten inert gas welding parameters to attain maximum tensile strength in AZ61A magnesium alloy

Magnesium and its alloys have been considered one of the best materials for automotive applications due its light weight and high strength to weight ratio. Metallurgical advantages of pulsed current tungsten inert gas welding (PCTIG) frequently reported in literature include refinement of fusion zone grain size, reduced width of heat affected zone, etc. In this paper, an attempt has been made to establish an empirical relationship is developed to predict tensile strength of the PCTIG welded AZ61A magnesium alloy by incorporating process parameters such as pulse current, base current, pulse frequency and pulse on time. Statistical tools such as design of experiments, analysis of variance, and regression analysis are used to develop the relationships. The developed empirical relationship can be effectively used to predict the tensile strength of PCTIG welded AZ61A magnesium alloy joints at the 95% confidence level. The results indicate that the pulsed current has the greatest influence on tensile strength, followed by pulsed on time, pulse frequency and base current.

► PCTIG welding parameters were optimized to obtain defect free sound welds. ► Response and contour plots were developed to identify the interaction effect of PCTIG parameters. ► Empirical relationships were established to predict the tensile strength. ► Developed relationships can be effectively used to find the optimum PCTIG process parameters. ► Manufacturers and design engineers to determine the process parameters for a specified tensile strength.