Determination of heat generation by correlating the interfacial friction stress with temperature in friction stir welding

A three-dimensional computational fluid dynamics (CFD) model is established to analyze the interfacial friction stress and the associated heat flux at the tool-workpiece interface in friction stir welding. A novel method is proposed to calculate the interfacial friction stress directly based on the yield criterion, without any need to determine the friction factor first. The interfacial friction stress is described as a function of temperature. The variations of interfacial friction stress, heat generation, temperature field, and material flow are numerically simulated. The predicted thermal cycle and geometry of thermo-mechanically affected zone are in good agreement with the experimentally measured ones.