Mesoscopic Damage Formation And Its Evolvement Characteristic Of High Efficiency Milling Cutter

Because of low energy consumption,low-loss and high efficiency,the high energy efficiency milling cutters are received wide attention at home and abroad.Furthermore,due to the lightweight design is commonly used to develop all kinds of high energy efficiency milling cutters,researching and controlling the milling cutters' damage is significant to develop the high energy efficiency milling cutters.The macroscopic damage of high speed milling cuter originates from the micro damage which is caused by the dissipation of atomic binding force in mesoscopic scale,so the damage has the characteristics of crypticity and paroxysm.There is not simple and direct contact relationship between the loads,the performances and the milling cutter structures of macroscopic and mesoscopic scale,so it is difficult to actively grasp the formation and evolution of damage.Therefore,supported by the National Natural Science Foundation project,"mechanism of wave dynamics damage of high energy efficiency milling cutter and multi scale collaborative design method"(51375124),in order to research the damage behavior and its characteristics of high speed milling cutter components,the damage sample of cutter components are extracted.Base on mechanical properties of cutter components material and Hopkinson pressure bar experiment,the damage types and its formation mechanism of milling cutter under different loads is analysed.According to the analysis,the macroscopic damage formation on high-speed milling cutter component has obvious trans-scale characteristics.And the research scales of cutter components are determined by scale division.By using MAAD method,the trans-scale transfer of cutter cutting force,centrifugal force and pretightening force are realized.Aiming at the trans-scale characteristics of damage formation of high speed milling cutter,and according to the content of material elements and the combination of atoms,the super-cell models of are established.By using minimum energy principle,the super-cell model is optimized so that the super-cell model is in a stable state.In order to make the mechanical properties of super-cell close to the milling cutter components which are treated by hardening and tempering,the mechanical properties of super-cell is improved by using high temperature relaxation and rapid solidification method.Base on molecular dynamics simulation,the evolution characteristics of super cells,especially the germinating,growing and aggregating of the vacant groups,are revealed in its deformation process,local destruction process and integral destruction process.According to the strain of supercell of milling cutter assembly,the change of mechanical properties under working load is analyzed,and the Debra number is used to characterize the stage of meso damage nucleation and expansion,and the coupling and competition relationship between mesoscale damage and scale evolution is analyzed.Accordingly,the trans-scale recongnition method about the damage of cutter components is proposed.Combined with the intrinsic and extrinsic characteristics of milling cutter damage,a simulation experiment is designed to analyze the response of milling cutter assembly damage to macro cutting parameters and structural parameters.Finally,based on axiomatic design and grey relation,the design method of milling cutter parameters is proposed on the premise of ensuring the cutting efficiency of the milling cutter.