Laser Cladding And Numerical Simulation For Aluminium Alloys

Due to the advantages of light density, good plasticity, superior corrosion resistance,easy workability etc, aluminum alloys are widely applied to variety fields. But because of itsdefects such as low intension, poor rub resistance limited its range. By making use of thetechnique of laser cladding, the overall performance a material can be improved. At present,the parameters of laser processing are chosen mainly by experiment and through experience.Numerical simulation for aluminum alloys is significant for optimizing parameters of lasercladding.In this paper, laser cladding of SiC on 6061 aluminum alloy was carried out using a 2kWCW Nd-YAG laser. Finite Element Method (FEM) was used to simulate the temperature fieldduring laser cladding, some experiments were carried out to verify the simulation results. Thecalculation in cladding process is a material nonlinear procedure that the material propertieschange with the temperature; choose the function of Gauss as heat source model, we canconveniently carry out the loading and unloading of the motional heat source by using theAPDL language; A mathematic model of transient thermal process in cladding is establishedto simulate the moving of the heat source, and simultaneously appropriate mesh was plotted;The problem of the fusion and solidification of material was solved by the method ofchanging the element material; Analyze the distribution of the temperature fields from theaspect of laser cladding process. The author systemically discussed the finite elementanalytical system of the cladding process by realizing the 3D dynamic simulating of lasercladding temperature field, then used the research result to simulate the cladding process ofsurfacing by FEM soft ANSYS. The microstructure, phase identification of the modifiedlayers were examined using scanning electron microscopy (SEM), X-raydiffractometer(XRD), respectively. Proving the result according to the simulation result.In this paper, a feasible dynamic simulation method on 3D cladding temperature fieldwas established, which provided theory foundation and instruction on optimizing the claddingtechnology and parameters. The simulated results show that the laser parameters can decidesamples' peak temperature on the surface and the distribution of temperature grads. The maximum temperature in the field was inversely proportional to the sweep speed and thefacular radius, and directly proportional to the laser power. The temperature grad was affectedlowly by sweep speed, but highly by laser power and facular radius. The experimental resultsshow mostly conformity compared with the simulated results. The best technology parameteris: laser power 1200W, sweep speed 5ram/s, facular radius 1.25mm.