Effect of tool pin profile on the heat generation model of the friction stir welding of aluminium alloy

Abstract

Abstract The present work aims to model the three-dimensional heat transfer coupled with the material flow model of 7075-T6 aluminium alloy material using the three tool pin profiles, square, pentagon, and hexagon, in the friction stir welding process. The temperature rise and fluid flow behaviour from the top to the bottom of the tool were evaluated. Also, the strain rate and dynamic viscosity variation were found near the tool pin and shoulder region. The results showed that the frictional contact heat between the shoulder surface and workpiece was responsible for the maximum heat generation. The probe area was minimum in the square tool pin geometry, which results in high heat generation due to the maximum shoulder surface contact area with the workpiece model. Furthermore, the analytical formula for calculating the heat generation on the tool shoulder/workpiece interface and the tool pin/workpiece contact region were also evaluated. The numerical modelling of heat generation was evaluated by COMSOL Multiphysics V5.3a software.