Analysis of Tool Feedback Forces and Material Flow during Friction Stir Welding

摘要

An innovative heuristic force model has been developed to characterize material flow induced by the Friction Stir Welding (FSW) process. When the rotating weld tool travels inside the plasticized material, the leading interfacial surfaces of the tool experience the prevailing pressure field (PPF) due to the tool travel motion. Furthermore, a plasticized shear layer of material is periodically extruded from the leading side to the trailing side of the weld tool by the rotational and travel motions of the weld tool. This periodic material flow introduces revolving pressure field (RPF) around the weld tool. Due to PPF and RPF, the tool feedback forces grow and evolve during the FSW process. A relationship between the pressure fields and the tool feedback forces was identified by the heuristic force model. The model has been simulated and the actual weld data was analyzed with regards to the simulation results.