Numerical Simulation On Temperature Field Of Aluminum Alloy In Laser-arc Hybrid Welding Process

Laser welding is a kind of welding method of high-quality and high efficiency, but it is rarely used because of high reflectivity and low absorption of aluminum alloy against the laser beam .MIG welding is general in the application of aluminum alloy welding, however, the penetration depth and welding speed is limited, which is also easy to lead to diversification of microstructure and properties, macro-deformation of the welding etc. Applying laser-arc hybrid heat source to butt welding for aluminum alloy not only increases the arc stability and thermal efficiency, but also effectively improves microstructure and properties of the joints and welding efficiency.This article establishes hybrid heat source model of laser-arc for butt 6061 aluminum plate that have the thickness of 6mm according to experimental results, respectively adopts the analytical method and finite element method to analyze and calculate welding temperature field of, and discusses heat source model when solving problems by means of the finite element method.The researching contents include that as follows: establishing three-dimensional analytical heat source model on point and line to plane in laser-arc hybrid welding according to heat transfer theory, writing computer programs by Newton's iterative on basis of C language and calculating the cross-section shape and size of the welding joint, adopting the integrated heat source model which is superimposed by Gaussian distribution heat source model, double ellipsoid heat source model and rotating body heat source model of heat flux radius of the linear attenuation in the depth direction, and simulating and analyzing joint temperature distribution for 6mm thick 6061 aluminum alloy in the laser-arc hybrid welding process by ANSYS finite element analysis software, and simulating and verifying the welding temperature field for 2mm thick 6061 aluminum alloy in the laser-arc hybrid process under applying the hybrid heat source model after the experimental verification.The research results show that: it can be gradually approaching to the results of the actual welding that the results of analytical solution through adjustment and revision of the thermal efficiency and laser attenuation coefficient. This method has a clear physical meaning, and solving process is simple and fast, but it can not analyze the dynamic temperature field when welding. The hybrid heat source that is superimposed by these three kinds of heat source is suitable for simulation analysis of dynamic temperature field of 2~6mm thick aluminum in the laser-arc hybrid welding process, or rather simulation results are very close to welding cross-sectional shapes of the actual weld joint.