A thermal coupling analysis model for friction welding of dissimilar materials based on thermodynamic principles

Rotary friction welding of dissimilar materials involves strong coupling between plastic flow, heat generation, and interfacial bonding. However, existing analytical models typically require predefined response variables or empirical friction coefficients. In this study, a thermomechanically coupled analytical model was developed for the steady-state, severe plastic deformation stage of rotary friction welding of dissimilar titanium alloys. This model is capable of directly predicting the axial shortening velocity (v_x), the width of the plastic deformation zone (B), and the average interface temperature (T_a), thereby fundamentally capturing the intrinsic coupling between process parameters and thermomechanical responses during the friction welding of dissimilar materials, as well as the asymmetric temperature and deformation responses characteristic of dissimilar welding. Experimental validation was conducted using a typical dissimilar titanium alloy system (TC4/TC17). A comparison of the predicted temperature distribution, axial shortening velocity, and deformation zone width with experimental results showed an error range of 10%–20%, thereby demonstrating the accuracy and applicability of the proposed model.