Simulation And Experimental Research Of Laser Cladding Ni60-WC On High-speed Steel Tool

Compared with cemented carbide tools,high-speed steel tools have excellent machinability and can be used to make complex shape tools.However,when the processing temperature of a high-speed steel tool is too high,the hardness will decrease,and the tool will be damaged.The laser cladding technology can repair the surface of the high-speed steel tool body.Cladding material can compensate for a high-speed steel tool’s hardness,wear resistance,and other processing properties.Aiming at the simulation and experimental performance of multi-layer and multi-channel laser cladding Ni60-WC cladding of high-speed steel tools,the research consists of three aspects:multi-layer and multi-layer cladding numerical simulation,laser cladding experiment,and high-speed steel tool cutting experiment.In the numerical simulation,the finite element method simulates the influence of laser power and scanning speed on the width and height of the cladding layer.The temperature field change at the junction of the cladding layer and substrate,the residual stress distribution of the cladding layer,and the influence of total deformation on the morphology of the cladding layer are simulated.The effect of the cladding layer without overlap,30%overlap and 50%overlap on the temperature and stress field is studied.The numerical simulation analysis of the temperature field at the cladding layer node and the stress field of the cladding layer matrix when the interlayer cooling time is 0.25s,0.5s,and 1s,respectively.Tool cutting experiment:The cutting motion of laser cladding strengthened high-speed steel tool and ordinary high-speed steel tool under different feed rates(0.2mm/r,0.3mm/r,0.5mm/r)was compared.When the scanning speed is from V=3mm/s to V=5mm/s,the melting width and height of the A1 cladding layer are reduced by 15.59%and 20.8%,respectively.When the laser power changes from P=23w to P=27w,the width and height of the A1 cladding layer increase by 6.55%and 55.56%,respectively.The simulation results of the lapping rate show a secondary remelting phenomenon in the lap area.The increase in laser power and the decrease in scanning speed will aggravate the temperature of secondary remelting.The simulation of interlayer cooling time shows that prolonging the interlayer cooling time can control multi-channel and multi-layer heat accumulation.When the interlayer cooling time is 1s,the temperature of node 4 decreases by 397 degrees.which effectively controls the interlayer heat accumulation.Laser cladding experiment:Pre-experiment screening process parameter range:laser power P(23w-27w),scanning speed(3mm/s-8mm/s),and cladding layer experimental defect analysis.Based on the Minitab response surface center composite method carries out 20 laser cladding experiments and establishes the regression prediction formulas of melting width and melting height.Tool cutting experiment:Under the experimental conditions of different feed rates(0.2mm/r,0.3mm/r,0.5mm/r),compared with the cutting motion of laser cladding strengthened high-speed steel and ordinary high-speed steel tools.The experimental results show that the types of chips produced in the cutting process of the two kinds of turning tools and the surface quality of the workpiece are the same.After laser cladding strengthening,slight wear occurs at the tip of the turning tool,and abrasive wear and adhesive wear occur on the rake face and the main flank face.The point of the ordinary high-speed steel turning tool and the leading cuttingedge cracks are worn.It cannot meet the cutting conditions.