Numerical Simulation Of Fluid Flow Field And Temperature Field Of Aluminum Alloy Laser Cladding

Due to its low density, high specific strength, good plasticity etc, Aluminum and its alloy are widely applied in many fields, like aerospace, auto industries and transportation and so on. But its poor surface performance including poor corrosion resistance and wear resistance restrict its wider application in the modern industries. Laser cladding can improve the surface properties of aluminum alloy, which is a surface treatment technology with good prospect. It can improve the surface properties of aluminum alloy. Quantitative analysis for fluid field, temperature field in laser melting pool has important theoretical and practical significance for predicting and controlling quality of harden surface.In this paper, the history of simulation for the temperature and velocity distribution in the laser cladding melting pool was reviewed. Then a summery of the laser cladding on Aluminum was presented. And, the Al-Y-Ni alloys coatings were prepared on Al-based alloy by laser cladding. The experiments indicate that the coatings have smooth and continuous surface, and metallurgical bond to the substrate. The cladding elements exist in the bottom of the cladding layer, which means the element was transfer by some strong fluid flow. The average hardness of cladding layer is higher than the substrate.This paper focused on the numerical coupling simulation of the fluid flow and heat transfer in the laser cladding melting pool based on the popular FEA software ANSYS. The movement of the solid-liquid interface was simulated in the method which was setting the temperature dependant fluid viscosity. Under the melting point of the aluminum alloy the viscosity of the flow was set as an extraordinary huge value. And the viscosity of the fluid was made as the real value after the metal was fused. The Marangoni convection was carried out by applied an equivalent continuous body force on nodes in the liquid-gas interface. The problem of the simulation on multi-species cladding system was also solved. The analysis result coincided with the actual laser cladding to some degree.The paper also analyzed the influence of the laser processing parameter on the melting pool shape, temperature distribution and the fluid flow field, drawing the conclusion that was the radius and depth of the melting pool increased along with the laser power rising and the decreasing of the scanning velocity. In the end, the overlapping laser cladding was simulated. The movement of the laser heat source was realized by the APDL.