Effect of planishing of pulsed and magnetic arc oscillation on mechanical properties of AA 5456 Aluminum alloy weldments A. Kumar 1,* and S. Sundarrajan 2 *1 Department of Mechanical Engineering, Kakatiya Institute of Technology & Science, Warangal – 506 015 , India. 2 Scientist ‘G ’, Defence Research and Development Laboratory, Hyderabad -500028, India. Abstract The present work pertains to the improvement of mechanical properties of AA 5456 Aluminum alloy welds through pulsed and magnetic arc oscillation welding processes. Pulsed and magnetic TIG welds exhibited better mechanical properties compared to continuous welds due to fine grain structure at the weld centre. Taguchi method was employed to optimize the pulsed and magnetic arc oscillation welding processes parameters of non-heat treatable AA 5456 Aluminum alloy welds for increasing the mechanical properties. . The same optimum condition was observed in all the properties either in pulsed or magnetic arc oscillation welds. Welds were made at the optimum conditions and subjected to planishing and mechanical properties were evaluated. Planished welds were shown better mechanical properties than unplanished welds due to redistribution of residual stresses. Regression models were developed to predict the mechanical properties within the selected range. Microstructures at the weld centre of all the welds of pulsed and magnetic arc oscillation welds were studied and correlated with the mechanical properties. The effect of peak current, background current, welding speed and frequency on mechanical properties of pulsed welding was studied and also the effect of amplitude and frequency on mechanical properties of magnetic arc oscillation welding was studied. Analysis of variance (ANOVA) was employed to check the adequacy of the developed models. Keywords: Pulsed TIG welding; Magnetic arc oscillation welding; Aluminum alloy; Mechanical properties; Microstructure; Planishing; Taguchi method; Regression models ---------------------------------------------------------------------------------------------------------------------------- *Corresponding author Tel : +91 9885055026 (P), +91 08702564888(O); fax: +91 08702564320 E-mail address: adepu_kumar7@yahoo.co.in (A.Kumar)