Transition of interfacial friction regime and its influence on thermal responses in rotary friction welding of SUS304 stainless steel: A fully coupled transient thermomechanical analysis

Abstract

Rotary friction welding (RFW) has proved to be a successful joining technology in advanced materials manufacturing. The highly transient thermal responses during friction heating, including heat generation and temperature distribution, are essential factors in the design and control of the RFW process. In this study, a 2D axisymmetric finite element (FE) model for the RFW process of SUS304 stainless steel is presented in order to investigate the transition of the interfacial friction regime and its influence on the transient thermal responses. By using the FE simulation, the in-process state variables, i.e., frictional stress and heat flux, and their spatial distribution at the welding interface are obtained. The FE simulation is validated by published experimental results. A new analytical model for the transient evolution of the friction regime is concluded from the FE simulation, which accurately predicts the shrinkage of the Coulomb friction zone while the Shear friction zone builds up from the workpiece periphery. Comprehensive analysis is conducted on the variation of interfacial heat flux, frictional stress and temperature resulted from the transition of friction regime. It is revealed that the transition of the interfacial friction regime from the Coulomb friction regime to the Shear friction regime is preferable for temperature homogenization at the welding interface.