Determination of Optimum Process Parameters and Residual Stress in Friction Welding of Thixocast A356 Aluminum Alloy

The quest of automobile industries for weight reduction and enhancement of the mechanical strength of components has been a major incentive for new manufacturing technologies such as thixocasting. It is therefore important that the welded joints of such components exhibit adequate strength and formability. The present investigation is on optimization of process parameters to achieve better weld quality obtained in friction-welded joints of thixocast A356 aluminum alloy. The optimum combination of welding parameters is obtained by using the analysis of the signal-to-noise (S/N) ratio based on the Taguchi method. Joint strength higher than the parent material strength is achieved with an optimum set of friction-welding parameters. In addition, residual stress analysis is carried out both experimentally and numerically. Comparisons between the experimental and numerical residual stresses are in good agreement with each other. The residual stress obtained is of low magnitude and compressive in nature.