Design and optimization of the process parameters for friction stir welding of dissimilar aluminium alloys

摘要

Friction Stir Welding (FSW) is one of the unique solid state welding technique that is fast gaining importance because of its ability to produce strong joints. The friction stir welding technique is effectively used in this research to join 5 mm thick dissimilar aluminium alloys of AA 7075-O and AA 5052-O grade. The effect of tool pin profile and tool rotational speed on the mechanical properties like micro-hardness and tensile strength are studied by the optimized Design of Experiments (DOE). The experiments are designed based on L16 orthogonal array considering TAGUCHI techniques for four design parameters and four parametric levels. The outcomes of experimental techniques are tabulated and TAGUCHI analysis, Analysis of Variance (ANOVA) are carried out in Minitab software. From the experimental results and statistical techniques, the methodology is validated and the outcomes of the experiments are found to be in close agreement with the statistical results with the error less than 5% of the mean difference value. The optimized process parameters for better micro hardness are as follows: tool rotational speed of 1200 rpm, feed of 120 mm/min, tool offset of 1 mm, and cylindrical tapered pin tool profile; while the optimized design of process parameters for better tensile strength are as follows: tool rotational speed of 1400 rpm, feed of 120 mm/min, tool offset of 1 mm and cylindrical tapered pin profile. The design and optimization of the process parameters for friction stir welding of dissimilar aluminium alloys is necessary for high strength weld joints.