Computational investigation of welding heat transfer characteristics and parameters effectiveness in mild steel linear friction welding

Numerical simulation of heat transfer represented an efficient tool for the prediction of the effectiveness of the selected welding parameters in industrial application of the linear friction welding (LFW). A fully coupled model was established to study the effect of welding parameters on the welding heat transfer characteristics in LFW of mild steel. The interfacial temperature increased quickly owing to friction heat generation, and stress distribution showed dynamic variations owing to the periodic motion. The energy ratio of friction work and plastic deformation work increased with increasing friction pressure, oscillation frequency, and amplitude, thus indicating the significance of heat generation by plastic deformation. The heat transfer characteristics were found to be highly dependent on the welding parameters. A practical mathematical equation correlating the average friction power with welding parameters was proposed and used to select the suitable welding parameters for a sound LFW joint. The simulated results indicated excellent agreement with the experimental measurements. Finally, microstructures of the experimental welded joint were investigated by consideration of the thermal process. It was hoped that the greater understanding of heat transfer behavior could improve the efficient of process optimization when joining steel as well as other metal materials.