Microstructure and mechanical properties on friction stir processed TIG welded dissimilar joints of AA5052-H32 and AA5083-H111 alloys by grey approach

In this investigation, the mechanical behaviour and microstructural examination of friction stir processed (FSP) Tungsten Inert Gas (TIG) welded aluminium dissimilar alloys has been studied. The research is proposed to enhance the mechanical characteristics of the aluminium alloy 5052-H32 and aluminium alloy 5083-H111 TIG FSP welded joints. Initially, the TIG welding was done to join aluminium alloy 5052-H32 and aluminium alloy 5083-H111 by employing a ER5356 filler rod. TIG welding is performed by using the following parameters: tungsten electrode diameter (2.4 mm), Current (170 A) and a shielding gas flow rate (argon) (11 l·min-1). Secondarily, the FSP is carried out on TIG welded aluminium alloy 5052-H32 and aluminium alloy 5083-H111 by using different tool rotation speeds (850 to 1050 rpm), tool traverse speeds (24 to 32 mm·min-1) and different number of passes (1 to 3) with a cylindrical pin less tool. The FSP parameters are designed by the Taguchi L9 array to compute the optimized parameters. The tensile strength, microhardness and % of elongation are determined for a total of nine specimens. Finally, the grey relational analysis (GRA) is employed to find out the best FSP parameter out of the set of FSP parameters. The optimal parameters of FSP are a tool rotation speed of 950 rpm, tool traverse speed of 28 mm/min and number of passes of 3. The number of passes are the most influencing factor when compared to other two FSP parameters.