Numerical Simulation Research On Linear Friction Welding Of45Steel

Linear Friction Welding (LFW), as a precision welding technology, has all advantages of friction welding, such as low cost, high reliability and less welding structure defects. Moreover, it can overcome the disadvantage that inertial friction welding restricts the shape of weld. Now, this technology has been successfully used to manufacture and repair the blisk of aircraft engines. Because linear friction welding is a plastic deformation with high nonlinearity, it is difficult to confirm the influence of welding parameters on welding process only by experimental study. Therefore, in this study the above mentioned key problem has been researched by using Finite Element Method. This is very significant in guiding practical.Based on software ABAQUS, a simplified3D coupled thermal-mechanical FE model of linear friction welding was established in this paper. During establishing model, a lot of key technical problems have been solved, such as geometric model of welding, material model and frictional contact model. Through the theory and experiment test, it is proved that the model is reliable.With the model established in this study, the thermo-mechanical behavior of45steel LFW was researched. It is found that temperature at the center interface can increase quickly to about800℃within Is, then increase slowly to about950℃. With the welding process proceeding, the temperature field becomes uniform across the interface, the axial shortening increase constantly and a lot of material is extruded to form flash. Finally, by comparing simulation result with experimental result, the reliability of the model is checked.Based the result mentioned above and the single factor analysis about vibration frequency, friction pressure and amplitude, it was emphasized how welding parameters influence welding result. The simulation results show that the increase of welding process parameters can improve the friction heat input, which can lead the temperature of weld interface rise faster and material can be softened earlier. Finally, more metal flow out of weld joint to form flash. For these reasons, the increase of welding process parameters can increase axial shortening. Moreover, the increase of vibration frequency can not only improve friction heat input, but also accelerate the friction heat conduction. With the increase of friction pressure, the upsetting of specimen will be more obvious. These factors can also promote the increase of the welding axial shortening.