Taguchi analysis of friction stir welded 5754 H111 aluminum alloy with 7075 T651 interlayer material

Abstract The aim of this research is to improve the ultimate tensile strength (UTS) of welded AA5754-H111 aluminium alloy joints incorporating a 7075-T651 interlayer by optimizing the Friction Stir Welding (FSW) process parameters. The investigation employs the Taguchi approach to examine the effects of three key parameters: interlayer thickness (0.8, 1.0, 1.2 mm), welding speed (30, 40, 50 mm min −1 ), and tool rotational speed (750, 850, 950 rpm). According to the ANOVA results, the most influential parameter is tool rotational speed (F-value: 329.59, p = 0.000), followed by welding speed (F-value: 26.52) and interlayer thickness (F-value: 19.05). The optimal parameter combination—950 rpm tool rotational speed, 40 mm min −1 welding speed, and 0.8 mm interlayer thickness—achieved a tensile strength of 185.96 MPa, which is close to the experimental value of 185 MPa, with an error of only 0.96 MPa (0.52%). With an R 2 value of 98.68%, the residual analysis and surface plots confirmed the accuracy and reliability of the regression model. This study provides valuable insights into optimizing mechanical properties in interlayer-assisted FSW joints using statistical design techniques.