Influence of Bobbin Tool on Microstructure, Residual Stress, Tool and Corrosion Analysis of Al 6063 Alloy Friction Stir Welded Joint

Present investigation deals with solid-state bobbin tool friction stir welding (BT-FSW), capable to join the materials that are problematic to weld by fusion welding process. This research examines how the process parameters, namely tool rotational speed, welding speed, and tool pin diameter, affect the mechanical performances of welded Al 6063 alloy sheets. Taguchi method was used to analyze the optimal process parameter for optimal tensile strength of welded Al 6063 alloy sheets. ANOVA was implemented to observe the prominence of parameters on the responses. SEM analysis, residual stress, fractography and corrosion test of the welded Al 6063 alloy joint and microstructure of the tool before and after welding were carried out. SEM analysis of bobbin tool depicted less wear and tear was found after welding. The tensile strength of weld joint was improved with the increased pin diameter and rotational speed. The evaluated optimal value of tensile strength of weld joint was 104.11 MPa, achieved at rotational speed of 1200 rpm, tool pin diameter of 5.5 mm and welding speed of 100 mm/min, having welding efficiency of 71.6%. The sample kept for 10 days has got the maximum corrosion rate of 0.34 %.