Numerical Simulation Of Laser Cladding Repair Technology For Aero Engine Curvature Blades

Aeroengines are the ‘heart' of all types of aircraft.The variable-curvature blades as their core components are prone to failure due to service in harsh working environments.Repairing failed blades that meet the repairable standards can effectively reduce engine operating costs.At present,the domestic variable-curvature blade repair technology is also immature.Therefore the process research of the aero-engine variable-curvature blade repair technology is an important issue to be solved in the aviation industry.Based on the industrial background of variable-curvature failure blades in high-pressure compressors,this research carries out numerical simulation research on laser cladding repair of variable-curvature blades,hoping to provide a scientific basis for the selection of process parameters of aero-engine variable-curvature blade repair technology.Carry out the numerical simulation research on the laser cladding repair of variable curvature blades.This article first establishes the overall model of the variable curvature blade.Secondly,the existing heat source model calculation program is improved by using the function functions and introduces local coordinate system.And the improved heat source calculation program is verified by other heat source models.Then the selection of heat source parameters in the double ellipsoid heat source model was optimized.Then the main process parameters in laser cladding single-layer and multi-layer repairs were further studied on the temperature field of the cladding layer of variable-curvature blades.Finally,the thermo-solid coupling method is used to explore the distribution of the process parameters of laser cladding single-layer and multi-layer repair on the stress field of the cladding layer of variable-curvature blades.The analysis of the temperature field of the cladding layer shows that the laser power in the laser parameters is directly proportional to the temperature of the molten pool.The laser scanning speed and the temperature of the molten pool present a downward convex decreasing function.The use of a reasonable single-layer laser scanning path can reduce the temperature of the molten pool.In laser cladding single-layer repair,the substrate preheating temperature is proportional to the temperature of the molten pool.Proper interpass cooling time can greatly reduce the temperature of the molten pool.The temperature of the molten pool increases with the increase of the overlap rate.In the laser cladding multilayer repair,there are three process parameters: the laser multilayer scanning path,the cooling time between layers and the laser multilayer power.The first process parameter has little relationship with the temperature of the cladding layer molten pool,and the latter two parameters can greatly reduce the temperature of the cladding layer molten pool.In the stress field analysis,when the substrate preheating temperature is increased from 220°C to 420°C,the two types of stresses of the cladding layer of the variable-curvature blades both show a downward trend.Most of the cooling time between passes has almost no effect on the stress change law of the cladding layer of the variable curvature blade.The stress curves of the two types of cladding layers of variable-curvature blades with no overlap and 66.6% overlap are almost the same and remain at a low stress level.The stress value of the cover layer of the variable-curvature blade shows an upward trend with the increase of the cooling time between the layers.Changing the power of the laser multilayer can greatly reduce the stress value of the filling and the cover layer of the variable-curvature blade.This project optimizes the third dynamic boundary and improves the existing heat source calculation program for the numerical simulation of laser cladding repairing variable-curvature blades.The research results can provide a scientific basis for the setting and optimization of repairing process parameters of variable-curvature failed blades.