Study On Cutting Performance Of Ball-end Milling Cutter With Variable Distribution Density Micro-texture And Cutting Edge

Titanium alloy still has high strength and toughness at low temperature,and its density is lower than most other materials,so it is widely used in aerospace and other sophisticated fields.However,due to its poor thermal conductivity and high viscosity,it is not conducive to processing.Therefore,in order to improve the machinability of titanium alloy,the cutting edge of ball-end milling cutter is passivated and micro-texture processing with variable distribution density is carried out to improve the efficiency and quality of titanium alloy milling.In this paper,the ball-end milling cutter is made of cemented carbide with cobalt content of 8%,which is passivated and processed by micro-texture with variable distribution density.Simulation and experimental research are carried out respectively,and the influence mechanism of micro-pit diameter d₁,micro-pit spacing l₁,micro-pit diameter d₂,micro-pit spacing l₂,distance from edge l and blunt edge radius R on milling force,workpiece surface roughness and tool wear is analyzed.Simulated annealing algorithm and stepwise regression method are selected to optimize the related parameters,which provides basic data for efficient cutting and tool development of micro-texture tools.Firstly,according to the analysis of friction and wear in cutter-chip contact area between cemented carbide ball-end milling cutter and titanium alloy,the mathematical model is established,and the geometric model of micro-texture with variable distribution density is determined.Then,the influence mechanism of blunt cutting edge on the mechanical and thermal characteristics of ball-end milling cutter is analyzed theoretically,which provides a theoretical basis for subsequent simulation and experimental research.Secondly,based on Deform finite element simulation software,the milling engineering of titanium alloy with ball-end milling cutter is simulated.Design the orthogonal test according to the parameter,the milling of titanium alloy with variable distribution density micro-texture ball-end milling cutter with cutting edge and without cutting edge are simulated and analyzed,and the influence of two conditions on milling force is compared.The influence trend is analyzed and studied,which provides reference for the subsequent optimization of micro-texture parameters with variable distribution density and blunt edge parameters.Thirdly,passivate the cutting edge of the ball-end milling cutter and prepare micro-texture with variable distribution density on the rake face.According to the orthogonal test simulated above,the corresponding experiment was carried out,and in order to have an optimization standard,a group of experiments of milling titanium alloy with ordinary ball-end milling cutter under the same cutting parameters were done.The milling force was collected in the experiment,and the data of rake face wear and machined surface roughness were observed after the experiment.Then,the influence of micro-texture parameters with variable distribution density and blunt edge parameters on cutting performance was analyzed,and the mechanism was studied,and the related parameter range was optimized.Finally,a multi-objective optimization model of cutting performance of cemented carbide ball-end milling cutter is established based on cutting force,tool wear and surface quality of workpiece according to the parameter range obtained by simulation and experimental optimization as constraint conditions.The optimization results of variable distribution density micro-texture parameters and blunt edge parameters were obtained by MATLAB using simulated annealing algorithm and stepwise regression method.