Application of the AHP for Optimization of Mechanical Properties Of Al-Mg-Si Alloy Using PCTIG Welding

This paper makes an attempt to investigate the influence of pulsed Tungsten Inert Gas (PCTIG) welding variables on the mechanical attributes like Impact Toughness, Hardness, Dilution as well as Notch Tensile Strength of welded specimen. The specimen used was Al-Mg-Si alloy. This alloy is extensively used in automotive manufacturing sector owing to its light weight which also helps to bring down the vehicular C02 emission. The addition of metalloid such as silicon in aluminum parent metal imparts high fluidity, good feeding characteristics and good hot cracking sensitivity to it. As opposed to normal Tungsten Inert Gas (TIG) welding, PCTIG welding applies variable current during operation. Peak current being higher in value facilitates sufficient penetration while base current helps in stabilizing the arc. However, owing to the development of inter-dendritic micro-structural features, PCTIG welding exhibits lower impact toughness and notch tensile strength compared to the parent metal. The Analytic Hierarchy Process (AHP) has been used in this work to maximize the mechanical properties and the related PCTIG welding parameters.