Study On Carbide Tool’s Surface Micro-texture Processed By Ultraviolet Nanosecond Laser And Its Cutting Performance

Titanium alloys have been widely used due to their excellent physical and chemical properties.However,due to the low thermal conductivity and high chemical activity of titanium alloys,they are typically difficult to machine alloy materials,resulting in high cutting temperatures during machining,leading to tool adhesion,diffusion,and oxidative wear.Especially under high-speed cutting conditions,severe wear shortens the time for the tool to reach the blunt standard.A large number of related studies have shown that the combination of microtexture and cutting tools can improve the contact conditions between the tool and chip,thereby reducing cutting force and temperature,reducing various wear mechanisms on the front and rear surfaces of the tool,and improving the service life of the tool.In this paper,surface microtextures are machined on the substrate of cemented carbide tools,and the mechanism of microtextures on the tool wear resistance during cutting is explored under different cutting speeds and texture morphology dimensions.Finally,it is concluded that surface microtextures within a reasonable size range can improve the cutting performance of cemented carbide tools for machining titanium alloys.In this paper,a parallel microtexture perpendicular to the main cutting edge is marked on the surface of a cemented carbide tool using laser processing.The influence and mechanism of laser processing parameters on the shape and size of the groove are investigated,and the processing methods for forming parallel microtextures with different spacing,depth,and width are obtained.Through mutual demonstration of two experiments,friction and wear tests and turning tests of micro textured tools were conducted,and the test results were analyzed.The mechanism of the impact of micro texture on tool wear was studied,and a more reasonable groove morphology and size were obtained.First of all,during the process of laser processing of micro textures,the influence of laser processing parameters on the spacing,depth,and width of micro texture grooves was investigated through a single factor test method,and more reasonable laser processing parameters were determined.A comprehensive test method was used to optimize the selection of micro texture tools that meet the expected morphological characteristics.Secondly,a reciprocating friction and wear test was conducted.On the basis of constant dry friction,load,and sliding rate,micro textured cutters with different groove spacing,depth,and width were ground against TC4 titanium alloy balls.Taking traditional non-textured cutting tools as a reference object,the effects and mechanisms of parameters such as spacing,depth,and width on friction and wear performance were investigated by observing the tool wear morphology,measuring the wear scar radius of TC4 titanium alloy balls,and analyzing the average friction coefficient of each group.The results of friction and wear tests on micro textured cutting tools show that the smaller the spacing between micro textures,the easier it is for wear debris to enter the groove and form a stable adhesive layer.When the groove is shallow,the friction reduction effect is slightly weak,but the adhesive layer formed is relatively stable;When the groove is deep,the friction reduction effect is enhanced,but due to uneven chip deposition,local adhesive wear occurs,leading to instability of the adhesive layer.The wider the groove,the smaller the friction area,thereby reducing the degree of wear.However,if the groove is too wide,shear plastic deformation will occur on the wear surface of the grinding ball,and the wear of the material at the edge of the groove will intensify.On the other hand,in friction and wear tests,the adhesive layer formed after the accumulation of wear debris has two sides.When the adhesive layer is relatively stable,the adhesive layer covers the tool surface instead of the tool substrate to participate in counter grinding,and new adhesive wear occurs on the surface of the adhesive layer;When the adhesive layer undergoes fatigue wear,it will break and fall off,thereby protecting the tool surface.However,when the adhesive layer is unstable,it may take away the tool material during the peeling process,thereby exacerbating tool wear.Finally,a dry turning wear test was conducted on TC4 titanium alloy bars.By comparing and observing the width of the wear band on the back face and the state of the chip bonding layer on the front face of non textured cemented carbide tools and micro textured cemented carbide tools at high and low cutting speeds,the mechanism of micro texture improving turning performance at different cutting speeds was analyzed.Then,by changing the spacing,depth,and width of the microtextures,three sets of dry turning experiments on TC4 titanium alloy were conducted to explore the impact of microtexture morphology parameters on the anti wear performance and the mechanism of action during the turning process,and the conclusions obtained from the friction and wear tests were again compared and verified.In the cutting process of microtextured tools,microtextures exhibit different mechanisms and functions in the face of different cutting speeds.During low speed cutting,the micro texture enables the adhesive layer to be stably and uniformly distributed on the rake face,thereby replacing the tool for cutting.During high-speed cutting,based on the contact condition that the groove is parallel to the chip,microtexture promotes the chip to leave the rake face smoothly,thereby avoiding the formation of a bonding layer,effectively reducing adhesive wear and diffusion wear.In turning wear tests,the mechanism of the influence of groove spacing,depth,and width on wear performance is consistent with the conclusions obtained from friction and wear tests.In addition,under the same cutting conditions,the final wear morphology of microtextured tools is better than that of non microtextured tools,mainly reflected in the improvement of adhesive wear,diffusion wear,and boundary wear.Based on the above research and conclusions,on the one hand,this study deeply studied the cutting characteristics of micro textured tools perpendicular to the main cutting edge;On the other hand,this study analyzed whether the adhesive layer that should be avoided as much as possible in traditional dry cutting titanium alloys will exhibit a positive effect on protecting the tool surface when it adheres stably.These two research contents have certain complementary significance for the current field of micro texture cutting tools.