Effects of Alternating Shielding Gases and post weld heat treatment on microstructure and mechanical properties of the GMA welded Joints of AA6061 Aluminium Alloy

Abstract The present paper focuses on the effect of alternating shielding gases and post weld heat treatment on tensile properties and porosity of GMA welded AA6061 joints. These properties of weld joints will be greatly influenced by microstructure and hardness of the welded joints. Hence, in this investigation tensile strength, porosity, microstructure and micro hardness measurements were carried out on the cross section of weldments. Investigations were conducted utilizing the Universal Testing Machine, Vickers Micro Hardness Tester, X-ray radiography, Optical Microscope, Scanning Electron Microscope (SEM), and X-ray Diffraction (XRD). Hence, in this research, a complete analysis has been carried out to understand the influence of shielding gases and post weld heat treatment on mechanical and metallurgical behavior of GMA welded joints of AA6061aluminium alloy. It was represented in this research; tensile strength of post heat treatment welded aluminum alloy was increased by 44.9% than non post treatment of welded joints. Also, the micro hardness has been greatly improved post weld heat treatment in AA6061 alloy specimens. It was evident from the micro structures and fractography analysis of the AA6061 alloy components.