WC含量对钴基合金复合熔覆层组织结构与性能的影响  

Effects of WC content on microstructure and properties of Co-based alloy composite cladding layers

作　　者：粟亮 仝永刚 胡永乐[1] 方靖中 王开明 伍鹏飞 SU Liang;TONG Yonggang;HU Yongle;FANG Jingzhong;WANG Kaiming;WU Pengfei(College of Automotive and Mechanical Engineering,Changsha University of Science and Technology,Changsha 410114,China)

机构地区：[1]长沙理工大学汽车与机械工程学院,长沙410114

出　　处：《粉末冶金材料科学与工程》2024年第6期486-495,共10页Materials Science and Engineering of Powder Metallurgy

基　　金：湖南省科技创新计划资助项目(2021RC3096);湖南省教育厅科学研究项目(23A0264);湖南省自然科学基金资助项目(2023JJ30038)。

摘　　要：为探究WC含量对Co基合金复合熔覆层组织结构及高温摩擦行为的影响规律,采用等离子熔覆工艺制备不同WC含量WC/Co基合金复合熔覆层,系统研究复合熔覆层的显微组织、硬度和摩擦磨损性能。结果表明:WC添加量较低时,熔覆层显微组织由胞状晶区、线状晶区和树枝晶区组成。随WC含量增加,复合熔覆层内部形成大量形状不规则且细小的(Co,W)C碳化物以及未溶解的WC颗粒,显著提高了复合熔覆层的硬度和摩擦磨损性能。复合熔覆层的显微硬度随WC含量增加而提高,w(WC)=40%的复合熔覆层硬度(HV)最高,达到752,较未添加WC的熔覆层提升了76%。WC强化复合熔覆层具有优异的耐磨性,其摩擦因数先减小后增大再减小,体积磨损量随WC含量的增加先减小后增大,w(WC)=20%的熔覆层具有最优的高温磨损性能,600℃的平均摩擦因数为0.235,体积磨损量为25.13×10^(8)μm^(3),磨损形式为氧化磨损与疲劳磨损。To explore the effects of WC content on the microstructures and high temperature tribological behavior of Co-based alloy composite cladding layers,WC/Co-based alloy cladding layers with different WC contents were prepared by plasma cladding process.The microstructures,hardness,and friction and wear properties of the composite cladding layers were systematically investigated.The results show that the microstructure of the cladding layer is composed of cellular,columnar,and dendritic crystal zones when the content of WC is low.As the WC content increasing,a large number of irregularly shaped fine(Co,W)C carbides and undissolved WC particles are formed inside the composite cladding layer,which significantly improves the hardness and friction and wear properties of the composite cladding layers.The microhardness of the composite cladding layer is enhanced with the increase of WC content,showing the best hardness of 752 with the WC mass fraction of 40%,which is 76% higher than that of the cladding layer without WC.The WC reinforced composite cladding layers exhibit excellent wear resistance.The friction factor decreases first then increases,and then decreases again,and the wear volume loss decrease firstly and then increase with the increase of WC content.The cladding layer with WC mass fraction of 20%shows the best high temperature wear performance,of which the average friction factor at 600℃ is 0.235,and the wear volume loss is 25.13×10^(8)μm^(3),the wear forms are oxidative wear and fatigue wear.

关 键 词：钴基合金 复合熔覆层 显微组织 硬度 高温磨损 

分 类 号：TG156.8[金属学及工艺—热处理]