Numerical Simulation Of Temperature Field And Flow Field During Laser Cladding Of Molten Pool

The process of laser cladding can be realized by adding cladding materials on the workpiece surface with high energy density laser heating. Own to the conduction of the material, the cladding materials and substrate skin layer melt rapidly, after which the laser cladding layer can be obtained. Molten pool can be formed by the interaction between the high power laser and the metal powder as well as metal matrix, the kinetics of metallurgical processes in which has a close relationship with the process quality. Heat transfer, mass transfer and convection coexist in the molten pool, which directly affect the shape of molten pool, the absorption of gases and inclusions, aggregation and overflow, components of organization and its metallurgical properties. Besides, the quality of the cladding layer is also closely related to the flow pattern of fluid. Therefore, the heat transfer, mass transfer and flow in laser molten pool are crucial on the microstructure and property of cladding layer. Consequently, the study on temperature field and flow field is the foundation of laser cladding. This paper adopts the finite element numerical simulation method to study the temperature field and flow field in laser cladding pool.Based on the theories such as heat transfer and fluid dynamics, three-dimensional finite element model is established by applying UG software, which is similar to the real cladding layer morphology. The temperature field of the single-layer single-channel laser cladding molten pool is simulated under the moving heat source by applying the ANSYS finite element software. Distribution of temperature field of the molten pool at a certain moment is studied and the characteristics of temperature field in the cladding process under different technological parameters are also obtained. The curves of the temperature and temperature gradient with specified paths are gained. Besides, influence of different process parameters on the temperature field is analyzed, which forms the basis of optimizing the process parameters of laser cladding.Besides, the finite volume method is also adopted. Temperature field and velocity field of the in laser cladding molten pool are simulated under moving heat source by applying the FLUENT software. The flow pattern of fluid in the molten pool is analyzed under different surface tension temperature coefficients.