A coupled thermo-mechanical model of friction stir welding

Abstract

A coupled thermo-mechanical model was developed to study the temperature fields, the plunge force and the plastic deformations ofAl alloy 2024-T351 under different rotating speed: 350, 400, and 450 rpm, during the friction stir welding process. 3-D FE model has been developed in ABAQUS/Explicit using the arbitrary Lagrangian-Eulerian formulation, the Johnson-Cook material law, and the Coulomb's Law of friction. Numerical results indicate that the maximum temperature in thefriction stir welding process is lower than the melting point of the welding material. The temperature filed is approximately symmetrical along the welding line. A lower plastic strain region can befound near the welding tool in the trailing side on the bottom surface. With increasing rotation speed, the low plastic strain region is reduced. When the rotational speed is increased, the plunge force can be reduced. Regions with high equivalent plastic strains are observed which correspond to the nugget and the flow arm.