Friction Stir Welding Tool Life Assessment Through Fatigue Analysis

Friction stir welding is a solid-state joining process used to weld various materials. Tool life is an important consideration when welding strong metals with the Friction stir welding technique (FSW). The current research aims to calculate tool life by mathematical derivation and simulation using ANSYS transient structural analysis. There are two tool materials and five-pin profiles to consider. The calculated tool life using mathematical formulation is within 15% of the simulation outcome. Further changes are made to the simulation to make the tool life estimate more realistic under FSW’s operation. PcBN tool has superior mechanical properties over the tungsten carbide tool, so the procedure started with the tungsten carbide tool. The conical pin profile is giving 31466 cycles of tool life, which is 70 min run time while working at 450 rpm rotational speed. As a result, for high-strength materials joining, the tool must be chosen based on tool life parameters. The addition of a 1.5 mm fillet at the pin-to-shoulder junction has improved the tool life by 1147 cycles. The PcBN tool is simulated with a conical tool with new pin profiles of conical with grooves and cylindrical fillet with grooves. The maximum tool life of 94018 cycles is obtained for the conical PcBN tool.