| The new energy automobile industry has developed rapidly,aluminum alloy body structure parts have been widely used,and various domestic automobile main engine manufacturers are competing to research and develop,in order to achieve automotive lightweight and increase the mileage of new energy vehicles.This article mainly focuses on aluminum alloy rear cabin structural parts,based on the finite element analysis platform for Simufact Welding,a three-dimensional Welding simulation model was established to obtain the variation rules of temperature field distribution and stress field distribution during the Welding process of aluminum alloy structural parts,and to explore the influence of different Welding currents and painting processes on the microstructure and mechanical properties of welded joints.The main research work is as follows:Firstly,based on Simufact Welding welding finite element analysis software,the basic research on MIG welding of 3mm thick 6063-T6 aluminum alloy T-joint is carried out,and the three-dimensional welding simulation model is established to explore the variation of temperature field distribution during welding.Comparing the simulation calculation with the test results,it is concluded that the peak temperature and temperature trends of the two measurement points are basically consistent,and the coincidence degree reaches 90%.At the same time,the simulated weld pool topography size is compared with the test results,and the weld width and the throat size match degree are 85%,which further verifies the accuracy of the welding finite element analysis and the selected process.The parameters and the rationality of the welding heat source.Then according to the welding process of the T-joint,the numerical simulation of the welding of the aluminum alloy rear compartment structural parts for the vehicle body is carried out.It is concluded that the residual stress of the rear cabin assembly is mainly concentrated near the weld.The welding current affects the stress distribution and deformation of the structural components of the rear cabin assembly.As the heat input increases,the residual stress after welding increases,and the welding deformation becomes larger.The amount of welding deformation is mainly reflected in the Y-axis direction at both ends of the rear longitudinal beam.The simulation simulation is consistent with the actual deformation amount,and the degree of coincidence is 80%,which has important guiding significance for practical engineering applications.Secondly,the influence of welding current on the microstructure and properties of 6063-T6 aluminum alloy T-weld joint was discussed.The results show that with the increase of welding current,the heat input increases,the tensile strength of the joint decreases gradually,and the microhardness value decreases.The grain size of the weld zone and the heat affected zone continue to grow,and the dimple The size becomes larger and the depth becomes shallower.Finally,the influence of coating process on the microstructure and properties of 6063-T6 aluminum alloy T-weld joints was studied.The results show that the coating process has a good strengthening effect on the mechanical properties of welded joints.Compared with the coating process,the tensile strength of the welded joint increased by 13%,the welding coefficient was 76% of the base metal;the microhardness of the heat affected zone was 18.8% higher than that before the coating process.At the same time,after the welding joints are coated,the Mg and Si atoms in the heat-affected zone continue to be enriched,and the acicular ??phase precipitation increases,and the mechanical strength exceeds the weld seam,resulting in the weakest area of the joint. |
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