Multi-objective Optimization of MIG Welding of Aluminum Alloy

Abstract

Aluminum AA6061-T6 (Al-Mg-Si) is a precipitation hardened aluminum alloy belonging to 6000 series having the intermediate strength and possesses excellent corrosion resistance. It has been widely used for fabrication of lightweight structure such as marine structure components, wings, and fuselages of aircraft structure, and bicycle frames etc. which requires a high strength-to-weight ratio. However, MIG welding of AA6061 material is very critical so, the selection of process parameter plays a major role in determining the quality of the weld joint. In this paper input parameter such as welding voltage, wire feed rate, and dynamic or arc force correction have been chosen. The experiments were conducted on semi-automatic pulse MIG welding machine according to the L ₉ orthogonal array with replication. The process parameters viz. welding voltage, wire feed rate and dynamic is significant in intelligent MIG welding machine have been considered as variables. The responses such as tensile strength, hardness and heat affected zone (HAZ) of welded joints of AA6061-T6 aluminum alloy have been investigated and optimized using Taguchi based grey relational analysis. From this multi objective optimization, it has been found that welding current is the most significant parameter followed by wire feed rate and dynamic factor for the intelligent welding machine under consideration.