Analysis And Numerical Simulation Of Temperature And Stress During Laser Cladding Process

Laser cladding is an advanced technology of surface treatment by which the alloy powder with high performance can deposit on surface of accessories made by cheap metal, the properties of the surface are improved, also there is small heat affected zone and small distortion of the accessories. Especially, LC (Laser Cladding) represents powerful to repair the wear or invalid surface of precious parts, moulds etc.There are four aspects researched in this paper:1 A quasi-stead system is defined based on the formation procedure of clad profile cross-section, and the relation between the laser processing parameters is investigated. Using the law of heat and mass conservation, the maximum and minimum threshold of laser power can be given.2 H13 power is preplaced on the surface of steel mould and is sintered by laser. The temperature and residual stress fields of the process are simulated by ANSYS, near gauss heat source model into account, using APDL (ANSYS Parameter Design Language) to control the density of thermal flow, Velocity and path of scanning. Three-dimensional (3D) model is constructed, and the distributions and histories of temperature and stress fields are obtained. Comparing with experimental results, it is found that the simulation is feasible.3 Analyzing the different laser power models using ANSYS software, it is shown that the maximum temperature,the maximum heating and cooling rate of cladding layer are directly proportional to the laser power, but the distribution of temperature gradient is almost the same. Increasing the laser power only has little effect on the decrease of the cooling rate and the residual stress. 4 Using ANSYS software to establish the different models, to the different starts of the laser beam, it is found that dent can be avoided on border if the laser beam starts working 2mm after the coating. Besides, the height decreases due to the surface tension. Through test and analysis, it can be known that the method can avoid dent effectively without the change of other processing parameters.