Study On Properties Of Cemented Carbide Tool Strengthened By AC Magnetic Field

Metal cutting tools are the main components of cutting technology in manufacturing industry.Nowadays,with the development of manufacturing industry,new lightweight and high strength materials have been widely used,which requires higher performance of cutting tools.Strengthening the hardness and toughness of cutting tools,reducing tool wear and chipping,and improving the quality of workpiece products have become the research hotspots in the field of metal cutting at home and abroad.The magnetic field strengthening technology of metal cutting tool is to transfer the magnetic field energy to the tool material through energy transfer,change the arrangement structure of atoms and molecules in the material,and change the metallographic structure and mechanical properties of the material.Compared with traditional tool strengthening technologies such as coating strengthening,magnetic field strengthening has the advantages of simple operation,less investment,quick effect,no pollution and no influence on the size of tool edge,and has broad engineering application prospects.In this paper,AC magnetic field treatment technology is used to strengthen cemented carbide cutting tools.The theory and method of electromagnetics,material science,metallography,tribology,metal cutting and other disciplines are used to study the influence of magnetization treatment on the performance of cemented carbide cutting tools and its mechanism.The main contents and conclusions of this paper are as follows:(1)The effects of AC magnetization on mechanical properties and microstructure of cemented carbide tool materials were studied.The experimental results show that the hardness of YT5 specimens can be increased by AC magnetic field hardening treatment.Different magnetization parameters have different effects on the hardness of YT5 specimens.The maximum increment of microhardness of YT5 specimens is 61 Hv.At this time,the hardness gain rate reaches 5.15%,and the Rockwell hardness of YG8 specimens increases 0.32 HRA.By comparing and observing the metallographic structure of the samples,it is found that the magnetic field strengthening treatment can cause or accelerate the dislocation movement of cemented carbide materials,increase the solid solubility of W and C in the bonding phase,refine the WC grain and reduce the grain edges and corners.In addition,? phase appears due to the increase of carbides in the microstructure,? phase can reduce the local coercive force and cobalt magnetism,thereby reducing the internal stress.The relationship among coercive force,cobalt magnetism and WC grain also changes in the metallographic structure.(2)The effect of AC magnetization on the friction and wear mechanism of cemented carbide tool materials was studied.The results show that magnetization treatment can change the main friction and wear modes of tool materials,reduce the friction coefficient and wear amount of cemented carbide materials,and reduce the wear rate of materials.Under the same test conditions,the average friction coefficient of the magnetized sample decreases by 2.9-7.9%;for YT5 sample group,the wear rate decreases by 13.2%;for YG8 sample group,the wear rate decreases by 15.8%.(3)The effect of AC magnetization on the cutting performance of cemented carbide tools was studied.Through milling experiments of different magnetic properties materials,the influence rule and mechanism of magnetic field are analyzed from three aspects: milling force,tool friction and wear,and surface quality of workpiece.The results show that when processing ferromagnetic materials,the AC magnetic field strengthening treatment reduces the wear of cutting edge,increases the cutting force and optimizes the surface quality of the workpiece.When processing paramagnetic material,the wear of milling cutter is reduced,the cutting force is basically unchanged,and the surface quality of workpiece is not significantly improved.