Simulation And Experimental Study On High Speed Milling Morphology Of Cr12MoV Die Steel

Cr12MoV die steel is widely used in die making industry because of its good corrosion resistance,wear resistance and fatigue resistance.The surface microstructure of the mold has an important influence on the service perf ormance and service life of the mold.The cutting parameters,workpiece materials,tool vibration and other factors also affect the surface microstructure of the mold to varying degrees.If we only rely on milling experiments to analyze the changing law of die steel microstructure,it needs a great cost.With the continuous improvement of high-speed milling simulation technology,matlab simulation can be used to change the cutting parameters to control the micro-morphology of the machining surface.Therefore,with the support of the national natural science foundation of China,this paper mainly studies the surface topography of high-speed milling Cr12 MoV die steel as the research object.The main research is as follows:Firstly,the formation mechanism of high speed milling surface,the row space residue of surface morphology and the formation process of feed residue were analyzed.Based on kinematics and geometry,the milling model of ball end milling cutter under static and moving state was established,and th e motion path equation of cutting edge line was obtained.Considering the influence of machining inclination Angle,tool vibration and deformation on cutting edge motion trajectory,the mathematical expression was obtained and the motion trajectory equation was modified to calculate the surface residual height,which provided a theoretical basis for the simulation of milling surface topography.Secondly,the cutting edge,workpiece and time step of ball end milling cutter are discretized.According to the motion path equation of cutting edge line,the discrete point cloud data of cutting edge participating in cutting are obtained.This paper introduces the geometric significance of mathema tical expression and weight factor of NURBS surface,fitting discrete poi nt cloud data with NURBS surface,and completing surface reconstruction by modifying weight factor and adjusting local surface.At last,the matlab simulation program was written and the surface topography was successfully simulated.Then,through the established simulation model of surface topography,the surface topography under different cutting conditions is simulated.The influence law of milling parameters on surface morphology quality was analyzed according to row spacing,feed residual height,3d arithmetic mean deviation and other morphology evaluation parameters.Finally,the milling test of Cr12 MoV die steel was carried out to analyze the influence law of each milling parameter on the surface roughness of the feature topography and verify the effectiveness of surface topography simulation.The effects of different initial phase angles and phase differences on surface topography and texture were investigated and analyzed by matlab simulation.This paper has certain guiding significance for the study of surface topography of high speed milling Cr12MoV die steel.