Simulation And Experimental Study Of Metal Surface Damage Repair Process Based On Friction Stir Welding

Friction stir welding repair is a new kind of defect repair technology compared with traditional fusion welding,there isn't secondary defects such as cracks and pores during the repair process,and it has broad prospects in the repair field.Metals can produce various defects during the process of casting.At present,there are many researches on the repair of friction stir welding defects,but there are still some studies on the analysis of FSW repair process by numerical simulation.This paper uses Deform-3d software to establish a three-dimension thermalmechanical coupling finite element model about the friction stir welding defects repair process and analyzes the temperature field,equivalent plastic strain and material deformation behavior of AZ80 magnesium alloy at different rotation speeds and different forward speeds during the friction stir repair process,surface morphology.Determine the welding tool structure,defect-free process parameters,and guide the test to improve the welding quality.According to the dynamic recrystallization model in the FSW process,the Deform-3d software is used to simulate the evolution of the organization.Through the Deform-3d software,the influence of the auxiliary heat source on the temperature field,equivalent plastic strain and surface morphology of the 45 steel are analyzed,and it is found that the influence of the auxiliary heat source on them is much smaller than the influence of the rotation speed and forward speed.Through Sysweld software,with the help of Fortran language in secondary development,the phase change model was imported into Sysweld,and the microstructure changes of 45# steel during the friction stir repair process were studied.Selecting AZ80 magnesium alloy as the experimental material,carrying out defects repair experiments under different process conditions,and analyzing the microstructure,mechanical properties and surface morphology of the welded joints.The temperature measurement experiment was carried out through a thermocouple and were compared by the simulation results.Verify the accuracy of the finite element model.