Optimizing the Pulsed Current GTAW Process Parameters to Attain Maximum Tensile Strength Using RSM

Abstract

In this investigation, an attempt has been made to predict the tensile strength of pulsed current gas tungsten arc welded (PCGTAW) AZ31B magnesium alloy joints using RSM incorporating process parameters such as peak to base current ratio, welding speed, pulse frequency and pulse on time as variables. The experiments were conducted based on a four-factor, five-level, central composite design matrix. The developed empirical relationship can be effectively used to predict the tensile strength of PCGTAW joints of AZ31B magnesium alloy at 95% confidence level. The results indicated that welding speed and pulse frequency has the greatest influence on tensile strength, followed by current ratio, pulse on time. Response surface methodology (RSM) was used to optimize PCGTAW parameters to attain a maximum tensile strength of 214 MPa (78 % of base metal strength) in the AZ31B Magnesium alloy joints.