Optimisation of Process Parameters during Friction Stir Welding of Aluminium 4423 T-Lap Joints using the Taguchi Method

Abstract

In this present investigation, the Friction Stir Welding (FSW) of similar Aluminium 4423 T-Lap joints has been carried out. The FSW is an energy efficient, environment friendly and versatile process that makes it a “green” technology. The Aluminium alloys have some important characteristics, such as high ductility, good resistance against corrosion, low cost and good specific strength and these alloys are widely used in automobile, shipbuilding and aerospace industries. The most important output response is Tensile Strength during the FSW Process. The main input variables that affect the output response are Welding Speed, Spindle Speed and Depth of Penetration. These effective process parameters have been selected based on the literature survey. The experiments have been done by selecting L9 Orthogonal Array and results have been optimised with the Taguchi Methodology. Significant process parameters have been identified by ANOVA. Statistical results (at a 95% confidence level) show that the percentage contributions of Spindle Speed, Welding Speed and Depth of Penetration are 50.83%, 48.9% and 0.24% on Tensile Strength respectively. The result shows that the Ultimate Tensile Strength value of 60 MPa has been obtained by the Taguchi's optimisation method. From the results obtained by ANOVA, it has been found that the Spindle Speed is the most significant parameter. Contour plot has been used to determine the desirable Tensile Strength and the corresponding operating conditions, during the FSW of Aluminium 4423 T-Lap joints. Contour plots are useful for establishing the desirable response values and operating conditions.