Optimization of Friction Stir Welding Process Parameters to Weld Cast A356 Aluminium Alloy Taguchi's Design of Experiments Approach

This paper presents an application of Taguchi's Design of Experiments, to identify the optimum setting of process parameters to maximize the tensile strength of friction stir welded cast A356 aluminium alloy. The quality of weldments in friction stir welding (FSW) process mainly depends on the factors such as tool rotational speed, welding speed and axial force. Taguchi's orthogonal array L₂₇, signal to noise ratio (S/N) and Analysis of Variance (ANOVA) are used to find the optimum levels and the effect of process parameters on tensile strength. To correlate the process parameters and the measured tensile strength, a mathematical model has been developed by multiple linear regression analysis. The mathematical model is found to be very useful to predict the tensile strength of friction stir welded cast A356 aluminium alloy. The optimum conditions to get maximum tensile strength are tool rotation speed of 1000 rpm, welding speed of 75 mm/min and axial force of 5 kN.