Fabrication And Properties Of Textured Tools Deposited With AlCrN Coatings

The concept and design idea of the AlCrN coated tools with a laser-textured substrate surface are proposed in this paper,and the AlCrN coated tools with a laser-textured substrate surface are developed combined the preparation technologies of surface textures and surface coatings.Meanwhile,the tribological behavior and the cutting performance of the developed tools are investigated.The possible mechanism of surface textures are discussed.Firstly,micro groove textures are fabricated by pulse fiber laser machine,and the effect of processing parameters on the textures morphologies are studied.The best processing parameters are received:pulse power of 14 W,scanning speed of 150 mm/s,frequency of 40 kHz and one-time scaning.According to the process parameters,the width of the microtextures is about 25 ?m,and the depth is about 26?m.Four different samples are prepared:YS8 carbide cutting tool(A);YS8 carbide cutting tool with micro-textures(B);AlCrN coated tool(C);AlCrN coated tool with micro-textures(D).Then,the effects of surface textures on tribological properties of AlCrN coated samples in sliding against AISI 660 austenitic precipitation hardening stainless steel are studied.The following conclusions are obtained:under dry condition,The friction coefficient in ascending order is D?C?B?A.Changing the sliding velocity and applied load,sample D achieve the lowest friction coefficient.Compared with the sample A,the friction coefficient of sample D is reduced by 10%-20%.A combination of micro-textures and solid lubricants can effectively improve wear resistance and reduce the friction coefficient and adhesions of the AlCrN coated surface.The friction coefficient in ascending order is D?B?C?A.The effect mechanism of the sample D is attributed to the lubricant film formed on the friction contact interfaces and then reduces the friction coefficient.Meanwhile,the grooves mainly sever for depositing wear debris,which reduces the abrasive wear and adhesions.Cutting tests are carried out on AISI 660 austenitic precipitation hardening stainless steel with the untextured AlCrN coated tool(TT),the AlCrN coated tools with groove-micro-textures(MCT),the AlCrN coated tools with radius-micro-textures(RCT).Results show that the cutting forces,friction coefficient between the tool-chip interfaces,and the cutting temperature of the developed AlCrN coated tools are significantly improved over that the conventional one.Compared with the TT tools,the cutting force of the MCT tools is reduced by 10%-30%and the cutting temperature of the MCT tools is reduced by 5%-15%.Meanwhile,compared with the TT and RCT tools,the Fe adhesion and adhesive wear on the developed AlCrN coated tools are observably decreased,and the MCT tool shows the best anti-adhesive property among all the tool tested.The mechanism of the MCT tool is illuminated.First,the micro-textures can effectively reduce the tool-chip contact lenth.Second,micro-textures can capture the wear debris,which reduce the abrasive wear of the rake face.Third,the presence of micro-textures on tool rake face can promote the lubricating fluids filtering into the tool-chip interface and forming the boundary lubrication.