Study On Cutting Performance And Wear Failure Mechanism Of CrAlYN Coated Cutting Tools

Coated tools which can improve the cutting performance,prolong tool life and increase the quality and accuracy of metal-cutting,are widely used in metal processing.According to the wear mechanism of coated cutting tools,the CrAlYN coated HSS tools are researched in order to explore the wear and failure mechanisms of CrAlYN coated tools,provide important refer-ence to optimize the coating process parameters and cutting parameters.In this dissertation,friction characteristics between tool-chip and tool-workpiece interface in metal-cutting process were investigated by applying the modern tribology theory and combining with Abaqus simula-tion of metal-cutting to analyze the reasons and nature of tool wear by which cutting tool per-formance for machining is proposed;The performance and adaptability of coated tools with advanced CrAlYN multiple-component composite coating prepared by closed field magnetron sputter ion plating technique are verified using drilling and milling experiment.The main contents are as follows:The models of turning and milling were established by Abaqus software.The simulation analysis of cutting characteristics for processing 45 steel shows that are vulnerable to be sub-jected to high cutting temperature,tool toughness(high cutting force)d cutting process,so HSS cutting tools should have higher hot hardness and better impact resistance.The drilling test of CrAYN coated tools shows that the coating has good hot hard-ness.CrAlYN coated tools have small cutting force and stable condition,especially the coated tools with 3.28%Y content have better cutting performance,and the cutting performance of the annealed tools has little difference.The milling test of CrAlYN coated tools shows that the coating has good toughness and impact resistance.Furthermore,the optimal cutting parameters of the milling cutter are obtained.The CrAlYN coated tools could extend the range of milling parameters,improve the machining efficiency and the anti-impact limitation of the tools,and prolong their working life.Wear mechanism research of cutting tool shows that:?The major flank wear mechanism of coating HSS twist drill was mainly abrasive wear and adhesion wear.When the cutting pa-rameter is larger,the oxidation wear and even coating flaking occurs in outer corner region.Tipping would happen when cutting the hard stock and the coating has little effects on modifi-cation of drill chisel edge.(2)The wear shape in major and flank corner of the coated milling tools is triangle.Coating can prevent the tool surface from oxidizing and slow down wear boundary extension.Tool wear mechanism is mainly abrasive wear in normal wear stage.The adhesion wear and boundary wear would be produced when the cutting parameters are improp-er.The main reason of tools wear is coating wear in outer corner area resulted from the cutting tool losing protective layer.