Research On The Preparation And Cutting Performance Of WC-Ni₃Al-based Cemented Carbide Tool Materials

With the development of dry cutting technology,cutting technology has put forward higher requirements on the cutting performance of tools.WC-Co series cemented carbide is the most widely used cemented carbide tool material in recent decades.However,the use of Co as the binder phase of cemented carbide exposes many deficiencies and shortcomings.The intermetallic compound Ni₃Al has the advantages of excellent mechanical properties and good high temperature oxidation and corrosion resistance.It is considered to be an ideal substitute for WC-Co cemented carbide binder phase Co.WC-Ni₃Al-based cemented carbide shows good application prospects as a new type of cemented carbide tool material.This paper studies the design,preparation,performance characterization and cutting performance of WC-Ni₃Al-based cemented carbide tool materials,in order to provide some reference for the development and application of new WC-based cemented carbide tool materials.The main research contents and conclusions are as follows（1）Research on the effects of sintering process and material composition on the mechanical properties and microstructure of WC-Ni₃Al-based cemented carbide tool materials.The WC-10%Ni₃Al cemented carbide has high comprehensive mechanical properties at1450℃sintering temperature for 15 minutes.Its bending strength,hardness and fracture toughness are respectively:1299.7MPa、1347HV₃₀、17.24MPa·m^1/2.Adding VC and Mo₂C can refine WC grains,adding 0.6%VC can increase the hardness of WC-Ni₃Al-based cemented carbide to 1413HV₃₀.Adding 1.5%Mo₂C can improve the relative density of WC-Ni₃Al-based cemented carbide,thereby increasing its flexural strength and hardness.（2）Research on the cutting performance of WC-Ni₃Al-based cemented carbide tools.The effect of cutting parameters on the cutting force and friction coefficient of WC-Ni₃Al-based cemented carbide tools was studied by single factor method based on right-angle dry cutting experiments.WC-Ni₃Al-based cemented carbide tools have a lower coefficient of friction.When the cutting speed is 280m/min,the friction coefficients of WC-Ni₃Al,WC-Ni₃Al-VC and WC-Ni₃Al-Mo₂C carbide tools are reduced by about 3.2%,4.8%and 7.9%respectively compared with YG6 carbide tools.The WC-Ni₃Al-based cemented carbide tool showed better wear resistance than YG6 cemented carbide tool in the cutting process.The main form of tool rake face wear is adhesive wear,accompanied by diffusion wear and oxidative wear.When the cutting speed was 240m/min,the wear life of WC-Ni₃Al,WC-Ni₃Al-VC and WC-Ni₃Al-Mo₂C carbide tools increased by 7%,15%and30.8%compared with YG6 carbide tools.（3）Research on the chip formation mechanism of WC-Ni₃Al based cemented carbide tools.The macro-morphology of WC-Ni₃Al-based cemented carbide tool chips presents annular helical banded chips.Compared with the YG6 carbide tool,the chip thickness of the WC-Ni₃Al-based carbide tool decreases,and the width of the lamellar structure in the chip free surface morphology increases.It shows that the WC-Ni₃Al-based cemented carbide tool has smaller shear angle and chip deformation than the YG6 cemented carbide tool.