Abstract: Reverse dual-rotation friction stir welding (RDR-FSW) is a novel variant of FSW process in which the tool pin and the assisted shoulder rotate reversely. Modeling and simulating the material flow and heat transfer phenomena is of great significance to completely understand the process mechanism. A three-dimensional model of RDR-FSW process is developed to conduct the numerical simulation of material flow and temperature profile during the process. Plastic deformation heat generation rate and friction heat generation rate during the process are both considered. The plastic material flow velocity fields, streamlines, strain rate and viscosity fields near the tool are studied. The predicted shape and size of thermal-mechanically affected zone(TMAZ) match well with the experimentally measured ones.

Key words: reverse dual-rotation friction stir welding (RDR-FSW);numerical simulation;heat generation model;heat transfer;material flow