Multiresponse Optimization of FSW Parameters for Cast AA7075/SiCp Composite

Abstract

Al/SiC-reinforced metal matrix composite is widely used in weight-sensitive applications such as portable and integrated circuit devices. The presence of SiC particles in aluminum alloys enhances material properties like thermal conductivity, density, and tensile strength. Reinforced aluminum matrix composite can be welded by friction stir welding (FSW) process. This investigation mainly focuses on optimizing the welding parameters of friction stir welded AA7075 with SiC reinforcement particle. The welding parameters considered are spindle speed, travelling speed, downward force, and percentage of SiC added to AA7075. The experiments are designed using response surface methodology (RSM). The responses considered are ultimate tensile strength and percentage elongation. Regression models are developed for the single responses and the results are analyzed using analysis of variance. Fuzzy grey relational analysis approach is then used to optimize the FS welding parameters by considering multiresponses. Highest grey fuzzy reasoning grade is obtained at a tool rotational speed of 1150 rpm, welding speed of 40 mm/min, axial force of 6 kN, and percentage of reinforcement of 20 wt% of SiC. The analysis using ANOVA for multiresponse case clearly indicates that the percentage of reinforcement is the most predominant parameter which requires more attention.