A COMPARATIVE ANALYSIS AMONG THE WELDED Al-6061 PLATES JOINED BY FSW, MIG AND TIG WELDING METHODS

Abstract

The present work deals with assessment of tensile strength, hardness, fracture behavior and microstructural changes in welded Al-6061 plates. MIG welding has been done with filler rod whereas no filler metal has been applied during TIG welding for comparing the results with FSW, a filler-less solid-state welding. The ultimate tensile strength (UTS) of MIGW sample has been found 75% and 111% higher than that of FSW and TIGW samples respectively. Also, the elongation shown by MIG joint is nearly 50% higher than that of other two welds. The tensile properties of two non-filler welds, i.e., FSW and TIG have been found similar. The fractography results have established the ductile behavior of all the three joints. The primary phase (bright Al-grains) of base metal zone (BM) with thin solid boundary has changed into thick dendritic shapes in the welded zone (WZ). Also, the coarse secondary phase of BM has converted into fine particle in WZ under the influence of rapid cooling. The WZ has been reported harder than HAZ in MIG and FSW plates whereas the HAZ of TIGW plate has been found harder than WZ due to accumulation of fine equiaxed secondary phase.