Numerical Simulation on Molten Pool Temperature Field of Pure Aluminum and Copper-Zinc Alloy Radiated by Chemical Laser
The thermal effect of material radiated by laser is one of the most important physics phenomena after aim material radiated by laser. The laser radiating on material, makes the temperature ascension of the material surface different degree. In this process, the occurrence heat transmit, mass transfer, organization and structure variety are occurred, all of these are the important factors that influence the performance of material which radiated by laser. The research on thermal effect of material radiated by laser is the physical foundation of laser process, laser heat treatment and laser-induced thermal damage. The research has positive effect on organization structure analysis radiated by laser and material surface modification.Material radiated by high power density laser is finished in short time. The heat-affected zone changed with different influence factors, such as kinds of material, material surface appearance, power density of laser, the function time, and the laser incidence angle etc. With these different factors, its organization appearance, the distribution characteristics and the temperature field have complicated varieties. And these varieties are hard to be measured by experiment method. Numerical simulation on material radiated by laser has been used to simulate the temperature field at the present time.ANSYS, a finite element analysis software, was used to simulate the temperature field of pure aluminum, the copper-zinc alloy radiated by laser. The variety of temperature on surface and inner of material with heating time was concluded through the simulation. The accuracy of simulation was done by contrast the result of simulation with the molten pool of real sample. A series of simulations on material radiated by laser with different power density are carried out to conclude the critical value of laser power density which can make the pure aluminum and the copper-zinc alloy melt through analyzing the temperature field of numerical simulation.According to the result of simulation, the temperatures of samples rise linearly. A “platform” can be seen when the temperature arrived at the melting point because of the latent heat of melting. When the energy accumulated beyond the latent heat of melting, the temperatures rise linearly again. In one second, the threshold power density value of aluminum melting is 4200-4500 W/cm~2, and the threshold power density value of copper-zinc alloy melting is 6100-7300 W/cm~2.