Research On The Method To Restrain The Wear Of Micro-arc Diamond Tool

Microstructures are widely used in aerospace,civil lighting and other functional surfaces,which can improve the dynamic performance of the aircraft,improve the life of the aircraft,and enable the aircraft to achieve the purpose of stealth.In order to obtain the high precision microstructure surface,the machining tool can not interfere with the microstructure,which requires the diamond tool tip arc must be very small.Micro-arc diamond tool plays an important part in the machining of micro-structure surface.Micro-arc diamond tool can grind out a tiny edge radius of the cutter,and can well reduce the size effect of the material and the plow-cut effect in the machining process,which is a feature not possessed by micro-milling cutter and other micro-tools.However,due to the extremely small radius of the tip of the micro-arc diamond tool,the strength of the tip is extremely small,and the wear of the tool is very easy to occur in the process of machining,and the wear of the tool will have a great impact on the surface accuracy of the microstructure.In order to solve the influence of microarc diamond tool wear on the surface accuracy,the method of suppressing micro-arc diamond tool wear is studied in this paper based on the aspect of tool parameters and machining parameters.In this paper,the cutting temperature field under the condition of Minimum Quantity Lubrication(MQL)is established and the selection standard of cutting fluid is determined.There are for two main reasons for macroscopic wear of micro-arc diamond tools: cutting force and cutting heat.The effective method of reducing cutting temperature is Minimum Quantity Lubrication.In order to explore the effect of Minimum Quantity Lubrication on cutting temperature,the cutting temperature field model of cutting tool under dry friction condition is established by using the Fourier heat conduction law,and the maximum temperature of cutting tool is obtained.Based on the cooling mechanism of Minimum Quantity Lubrication,the boundary film is regarded as a layer of heat-conducting medium in this paper,and the tool temperature field model under the condition of boundary film is established by using the Fourier heat conduction law,and the maximum temperature of the tool is obtained.Armed with this model,the maximum temperature of cutting tool under different operating conditions is solved,and the criterion for selecting cutting fluid is obtained.The finite element software was utilized to simulate the cutting process under the action of different cutting fluids,and the theoretical model was verified.In this paper,the force model at the cutting edge and the wear-resistance factor model at the cutting edge are established,and the crystallographic planes combination mode of the micro-arc diamond tool is optimized.The micro-arc diamond tool begins to wear at the tool tip.The best way to increase the strength of the tool tip is to choose the appropriate crystallographic planes combination.In this paper,the force model of tool rake face is established based on the Hencky stress theorem and the J-C constitutive equation,and thestress distribution model of tool rake face is obtained.Then,based on the characteristics of micro-arc diamond tool edge area,according to the relevant knowledge of fracture mechanics,using the theory of stress intensity factor,the force model of cutting tool edge area is established,and the conclusion that the tool edge area will be subjected to a large alternating load in the cutting process is obtained.In this paper,based on the dynamic microstrength model of different crystallographic planes and different cutting edge areas,the wear-resistance factor model of the cutting edge of a typical combination of crystallographic planes was established by using the weighted superposition average method,and the combination mode of crystallographic planes was optimized based on this model.The Molecular Dynamics was used to simulate the cutting process of different combined cutting tools,and the theoretical model was validated.Tool geometry parameters and machining parameters have a great impact on cutting force and cutting heat,thus affecting the wear rate of the tool.Based on Deform finite element software,this paper simulates the cutting process under different tool parameters and cutting parameters,and obtains the variation trend of cutting force,cutting temperature and cutting stress along with cutting parameters and tool geometric parameters.The simulation results show that the geometric parameters and cutting parameters cannot be optimized from the aspect of cutting force and cutting temperature.Therefore,using the Usui wear rate prediction model,the wear rate under different variables was obtained according to the maximum tool stress and cutting temperature values under different variables obtained by simulation.Through comparison,the influential trend of different variables on tool wear is obtained,and the parameters with the greatest influence on tool wear are obtained.