NUMERICAL SIMULATION OF THE MATERIAL FLOW INFLUENCE UPON HEAT GENERATION DURING FRICTION STIR WELDING

Friction stir welding is a solid state welding technique using a welding tool for carrying out material joining. In performing this process, the welding tool is deforming the workpiece material in the welding zone, forcing it to travel, mix and depose as a weld; and in the whole welding cycle, the welding tool is initiating the heat generation. To estimate the generated heat amount is a challenging task requiring a multidisciplinary approach as well as an analysis of many influencing factors. The material flow around the welding tool appears almost throughout the whole cycle of welding, but it is never considered as a factor involving the heat generation process. The paper is giving a view of the possible influence of the material flow on heat generation as well as numerical simulation that includes a procedure for explanation of the material flow around the welding tool. Numerical simulations have given the results which are then compared to each other; the goal is to show the extent to which the material flow influences the generation of heat in the friction stir welding.