Investigation on effect of pin shapes on temperature, material flow and forces during friction stir welding: A simulation study

Tool pin geometry plays an important role in the weld strength of friction stir welding process. In the current work, a thermo-mechanical model is developed to study the effect of three different pin shapes, namely, cylindrical, square and triflat, during friction stir welding process. The developed model is validated with the temperature, force and spindle torque at different welding conditions. Among the three geometries, triflat pin produced higher temperature, and strain rate. Material deposition for the square pin is stretched toward the advancing side while it is uniformly distributed for the triflat pin. Material rotates multiple times with the flat surfaced pin as compared with cylindrical pin.