Multi-Objective Optimization to Specify Optimal Friction Stir Welding Process Parameters for Dissimilar Mg Alloys (AZ31 and ZM21)

Abstract

Friction Stir Welding (FSW) of dissimilar magnesium alloys AZ 31 and ZM 21 is prominent for enhancing the mechanical properties of welded joints. Experiments were conducted to measure the impact of process parameters such as rotational speed of the tool, tool pin profile and axial load. The performance responses considered for evaluation were the tensile strength of the joint and weight loss in the salt fog corrosion test. To analyze the data effectively, a modified Taguchi approach was adopted, allowing the development of empirical relationships between the output responses and process variables. The validity of these relationships was confirmed through a thorough comparison of test data. Additionally, this method yields estimated ranges for output responses. The primary objective of this study is to determine the optimal process parameters that maximize tensile strength while minimizing the weight loss during the salt fog corrosion test. Utilizing Analysis of variance (ANOVA) data analysis, the optimum parameters were identified and validated through a confirmation run. The results indicate that the tool pin profile and rotational speed are the most influential parameters, significantly affecting the responses. Whereas the axial load did not demonstrate a significant impact on the FSW process. Test data are within/close to the expected range.