| With the development of technology,new materials with high melting point and low thermal conductivity have been widely used in modern industry.However,these materials have a great challenge in machining,because the low thermal conductivity of the materials leads to the rapid rise of the temperature in the cutting zone,which aggravates the tool wear.The rapid scrapping of low-performance tools and the high cost of high-performance tools,or the use of coolant,undoubtedly cause a lot of resource waste and environmental pollution.In order to implement the strategy of sustainable development,a mass-produced multi-layer coating textured cutting tool has been researched and developed,which effectively combines the low energy consumption,green and environment-friendly minimum quantity lubrication(MQL)technology to improve the machining performance and life of cutting tools.Based on the powder metallurgy molding method,a kind of cemented carbide tool with micro groove texture and YS2 T matrix material was prepared.In order to explore the influence of groove size on cutting performance,groove texture is designed according to the width;The two kinds of grooves are parallel to the main cutting edge,and the other dimensions are the same except the width.Then,the hardcomposite multilayer coating Al Cr N/Ti N was deposited on the tool surface by PVD coating method.The thickness of the micro groove texture region was uniform,but there were micro pits and white droplet defects on the coating surface.In order to study the properties of the surface texture of the composite coating,the friction and wear test and the surface contact angle test were carried out.In the friction and wear test,GCr15 steel ball was used as the friction and wear pair to rub the workpiece surface.The results show that the textured surface with composite coating exhibits lower friction coefficient;The vibration amplitude of the friction coefficient curve is smaller than that of the normal NT tool,and the ball wear is much less.The effect of oil lubrication makes the friction coefficient smaller,and the closed groove texture shows its ability of oil storage and supply.The contact angle test shows that the water droplet contact angle of CPT1 is 43% less than that of NT,and the vegetable oil droplet contact angle is smaller than that of water droplet.The cutting force,tool wear and chip morphology of titanium alloy TC4 were analyzed by comparative turning tests under dry and MQL conditions.The experimental results show that the cutting force of the tool with surface characteristics is smaller than that of the normal NT tool.The air cooling of MQL and the function of atomized particle lubricating oil combined with the function of surface texture to store lubricating fluid can effectively improve the cutting interface friction,inhibit the chip adhesion and tool wear.In addition,the chip deformation caused by the tool with surface features is smaller.The simulation experiment of cutting titanium alloy was carried out by using Advant Edeg FEM finite element analysis software,and the cloud image of the simulated cutting temperature was intercepted.The results show that the surface texture and MQL weaken the thermal diffusion on the tool to a certain extent,and the cooling effect of the surface coating is not obvious.Finally,the tool sub surface temperature was measured by the artificial thermocouple method.The results show that the cutting temperature of the tool with the surface groove texture of the coating is reduced by 11%-21%. |
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