Experimental analysis on friction stir welded AA 7075/AA 6061 using Taguchi grey relational analysis

Abstract In recent years, the applications of aluminium and its alloys are inevitable in aerospace, automobile, railway and shipbuilding industries due to its strength to weight ratio, resistance to corrosion and machine ability. In this experimental study, an effective approach, Grey Relational Analysis (GRA) is a novel methodology substantiated for optimizing the dissimilar aluminium alloys. The process parameters for AA 7075 and AA 6061 considered with the specimen thickness of 6 mm were experimentally examined by friction stir welding (FSW) technique. In FSW technique, tensile properties have been investigated, which exhibits superior metallurgical and mechanical properties after the post weld treatment. Moreover, the multi response optimization with L9 orthogonal array being carried out to process the optimized parameters on FSW nuggets and ANOVA (Analysis of Variance) resulted ascertains the mathematical responses to minimize the cracks, defects and flaws during the solidification and recrystallization processes. In spite of numerous commercial applications, the aluminium and its alloys are exploited to yield the intense tensile strength. The GRA is codified by the optimum parameters and the experimental number 8 graded the utmost tensile strength. This investigation facilitates to accomplish the enhanced mechanical properties and techniques in FSW over conventional welding process.