超声滚压强化对CoCrFeMnNiM(M=Ti,Mo)高熵合金激光熔覆层耐磨性的影响  

Effect of Ultrasonic Surface Rolling Extrusion on the Wear Resistance of CoCrFeMnNiM(M=Ti,Mo)High-entropy Alloy Coatings

作　　者：刘昊[1,2,3] 高强 戴剑博 李晓佳 杨海峰 韩静[1] 郝敬宾[1,2,3] LIU Hao;GAO Qiang;DAI Jianbo;LI Xiaojia;YANG Haifeng;HAN Jing;HAO Jingbin(School of Mechanical and Electrical Engineering,China University of Mining and Technology,Xuzhou 221116,China;Jiangsu Province and Education Ministry Co-sponsored Collaborative Innovation Center of Intelligent Mining Equipment,Xuzhou 221116,China;Jiangsu Key Laboratory of Mine Electromechanical Equipment,Xuzhou 221116,China)

机构地区：[1]中国矿业大学机电工程学院,徐州221116 [2]江苏省矿山智能采掘装备协同创新中心(省部共建),徐州221116 [3]江苏省矿山机电装备重点实验室,徐州221116

出　　处：《中国表面工程》2022年第6期107-115,共9页China Surface Engineering

基　　金：国家自然科学基金(51905534);江苏省自然科学基金(BK20210495);江苏高校优势学科建设工程(PAPD)资助项目。

摘　　要：CoCrFeMnNi高熵合金较低的硬度和较差的耐磨损性能限制了其在表面工程领域的应用。利用激光熔覆技术制备强化的CoCrFeMnNiM(M=Ti,Mo)高熵合金熔覆层,并通过超声表面滚压(USRE)技术强化熔覆层表面。采用XRD、FSEM、EDS、AFM、显微硬度计和摩擦磨损试验机等研究USRE处理对高熵合金激光熔覆层的微观组织、表面形貌、力学性能和摩擦学性能的影响。结果表明:CoCrFeMnNiTi高熵合金激光熔覆层由面心立方(FCC)结构的固溶体相和TiC原位析出相组成,CoCrFeMnNiMo高熵合金激光熔覆层仍由单一的FCC固溶体相组成。USRE处理后涂层的相构成均未发生变化,但CoCrFeMnNiMo涂层的晶粒尺寸得到更明显的细化。USRE处理降低了高熵合金激光熔覆层的表面粗糙度,提高了残余压应力和显微硬度,并且USRE处理对CoCrFeMnNiMo涂层的效果提升更加显著。经过相同工艺参数的USRE处理后,CoCrFeMnNiTi高熵合金激光熔覆层的体积磨损率由1.90×10^(-4)mm^(3)/(N·m)降低到0.71×10^(-4)mm^(3)/(N·m);但由于磨损机制的转变和表面脆性的增大,CoCrFeMnNiMo高熵合金激光熔覆层的磨损率反而上升。探讨了超声表面滚压处理对高熵合金涂层的适用性,可为高熵合金涂层耐磨性的强化提供参考。The poor hardness and wear properties of CoCrFeMnNi high-entropy alloy(HEA)greatly limit its application in surface engineering,so the enhanced CoCrFeMnNiM(M=Ti,Mo)high-entropy alloy coatings are prepared by laser cladding,and the surface is then processed using ultrasonic surface rolling extrusion(USRE).The microstructure and mechanical properties(residual stress,microhardness,wear resistance)of the coatings are investigated.The results show that Ti-doping leads to the TiC precipitation in the CoCrFeMnNi coating,while the CoCrFeMnNiMo coating is still comprised of a single FCC solid solution phase.USRE treatment reduces the surface roughness,and increases the residual compressive stress and microhardness of the HEA coatings.Besides,USRE treatment has a more significant effect on the CoCrFeMnNiMo coating.After USRE treatment with the same processing parameters,the volume wear rate of the CoCrFeMnNiTi HEA coating declines from 1.90×10^(-4)mm^(3)/(N·m) to 0.71×10^(-4)mm^(3)/(N·m).However,the wear rate of CoCrFeMnNiMo HEA coating increases due to the change in wear mechanism and the increase of surface brittleness.The applicability of USRE treatment to HEA coatings is discussed,which provides a reference for wear resistance enhancement of HEAcoatings.

关 键 词：超声表面滚压 激光熔覆 高熵合金 显微组织 耐磨性 

分 类 号：TH117[机械工程—机械设计及理论]