Study On Numerical Simulation Of Temperature Field And Improvement Plan In Laser Deep Welding Aluminum Alloy

Laser welding technology has advantages of high rate,high precision,high reliability,which is widely applied in industrial production.Aluminum alloy laser welding is a complicated physicochemical process of aluminum alloy reflectivity,the coefficient of reflectance and thermal conductivity are high and large,laser welding of aluminium alloy is easy to produce the defects such as surface subsidence and internal porosity,the research process of the laser welding with test need the long time and high cost of materials,the laser welding of aluminium alloy are researched with test and numerical analysis method by who are at at home and abroad.the selection of the heat source in the numerical simulation is the key to the simulation calculation,the paper selects double gaussian cylindrical heat source to complete the simulation of the 3d temperature field,studied the effect rule about the processing parameter of the laser welding of thin plate aluminum alloy on weld formation,and the experimental verification,that has important academic theory value and practical significance.The welding materials is 1 mm thick 6061 aluminum alloy,and the model of laser is YLS-2000.First of all,I analyze thoroughly the domestic and foreign research situation of laser welding numerical simulation,combined with the material characteristics of thin plate aluminum alloy,put forward the technical scheme to use the double gaussian cylindrical heat source model,and load the model by customized UDF program of FLUENT software,established 3-d numerical simulation model of laser welding of 1 mm thick 6061 aluminum alloy,complete numerical simulation of temperature field of deep penetration laser welding of aluminium alloy.Secondly,according to the analysis of the numerical simulation results,has determined the research program of process test,and through many test results,adjust the grid and solution parameters,until the simulation results are in good agreement with those obtained in the test.Finally,summarized the results analysis of simulation and experiment,obtained the influence law of process parameters on the weld formation,provides quantitative data reference and theory basis of numerical simulation for laser welding of thin plate aluminum alloy.This paper introduces two kinds of solutions to improve the weld quality.One is that changed the workpiece angle,has used the research method that the numerical simulation combining with process test,has confirmed the welding way does improve the effect of the defects that the collapse and hole.Another is the laser repeated the welding,has used only the method of the process test,has got the kind of welding method can improve the effect of the defects that the hole in the absence of penetration,but not has applied in the case of penetration.