Research On The Tool Wear Mechanism Of Al₂O₃-based Ceramic Cutting Tool Based On Discrete Element Method

Al₂O₃ ceramic cutting tool have been widely used in manufacturing industry because of its high wear resistance,high melting point,good chemical stability and lower prices.However,its brittleness,bending strength and impact resistance performance is poor,in the process of machining,with strong mechanical shock and thermal shock,tool was broken easily.Tool wear can affect the work-piece machining quality,machining efficiency and manufacture cost.It is necessary to simulate and analyze the process of A1₂O₃ ceramic cutting tool wear.Different cutting tool materials under different cutting condition machining different work-piece materials,the shape of tool wear and the dominant wear mechanisms also may not be the same.So this article research process of Al₂O₃ ceramic cutting tool wear with discrete element method,and study the effect of cutting parameters on tool wear.In order to improve the processing quality and provide basis for rational selection of machining.In this paper,based on the discrete element method,using PFC2D software respectively established BPM model of ceramic material and work-piece material.By uniaxial compression test,the Brazilian test,three point bending test and fracture toughness test calibration the microscopic parameters of A1₂O₃ ceramic material.Using the tensile test calibration the microscopic parameters of 45#steel.After checking the actual model can characterize mechanical performance,the calibration value is consistent with the literature of reference.In this paper,the ceramic cutting tool wear process,wear form,wear mechanism are analyzed in theory.On the basis of Merchant cutting model,established the theoretical model of the abrasion quantity.According to the mathematical model analysis,ceramic cutting tool hardness,fracture toughness and rake angle inversely proportional to wear,the cutting speed and cutting depth are in direct proportion to the wear.This paper considers the influence of the temperature field and the bonding effect in the process of cutting,established a two-dimensional discrete element model for cutting tool wear.To simulate the evolution process of the formation and extension of crack,and the evolution process of material peeling off.Using single factor method analyzes the cutting depth,cutting speed,cutting tool rake Angle and different alumina ceramic material effects on tool wear.Establish a set of paramenters which can get high surface quqlity,reduce tool wear and increase the processing efficiency.At the same time the simulation data and the th eoretical results were compared,the comparative results further demonstrates the effectives and resonable of the simulation software of discrete element method.