Optimization of hybrid ultrasonic frequency pulsed VP-GTAW process parameters on tensile properties of AA 5456 alloy

Abstract

Tensile properties optimization of AA 5456 aluminum alloy was carried out with hybrid ultrasonic frequency pulsed variable polarity gas tungsten arc wending (HPVP-GTAW). An orthogonal method was employed to conduct the experiments, and the tensile properties of AA 5456 aluminum alloy welded joints were measured and analyzed. Regression models were developed based on the least square estimation by taking tensile strength, yield strength, percent elongation, and ratio of reduction in area as response functions of variable polarity frequency f L, pulse frequency fH and a dimensionless parameter Ψ, which were calculated by background current Ib, peak current Ip, and pulse duration δ, respectively. The developed regression equations were checked for validity by coefficient of correlation r2 and confirmatory experiments. Optimum parameters of HPVP-GTAW were achieved through the discussion on response surfaces and contour plots drawn using the regression equations.