Thermal Analysis on Different Aluminium Alloys Using Friction Stir Welding

Friction Stir Welding (FSW) is a solid state welding process where plastic deformation takes place at the stir zone to join similar as well as dissimilar materials together. Various numerical and experimental FSW research has already been conducted on similar and dissimilar metals but limited work has been done on the thermal analysis of different alloys. Earlier works on FSW have dealt with only a few aspects of thermal analysis in the case of different alloys. In this context, the present work discusses the computational analysis of heat generation in the case of different aluminium alloys using COMSOL® software. A few numbers of experiments were conducted utilizing the subsequent process parameters: a rotating tool speed of 800 rpm, a traverse speed of 7.5 mm/min, and a tool tilt angle of 0°. This study aimed to validate the numerically generated thermal profiles with the experimental data received from the literature. With the increase of axial force, the temperature increases on the bottom as well as the top surface of the plate, while the welding and tool rotational speeds are constant. With the increase in welding speed, the surface’s maximum temperature decreases for AA6061-T6 and AA6061 alloys. Maximum temperatures of 934.55 K and 932.84 K are observed at 2 mm/s welding speed and 18kN axial force for AA6061-T6 and AA6061 alloys, respectively. But for the Al2024-T3 the maximum temperature of 915.4 K can be observed at 10 mm/s welding speed. Weld speed affects the residual thermal stress for the different alloys. Temperature received from the current numerical model and experimental data validated, and the variance in both the results is found to be <10%.