TiB_(2)含量对TiB_(x)/Ti合金涂层组织及摩擦学性能的影响  

Effect of TiB_(2)Content on Microstructure and Tribological Properties of TiB_(x)/Ti Alloy Coatings

作　　者：寇斐凡 岳赟 杜志浩 杜三明 陈德强 张永振 KOU Feifan;YUE Yun;DU Zhihao;DU Sanming;CHEN Deqiang;ZHANG Yongzhen(National United Engineering Laboratory for Advanced Bearing Tribology,Henan Luoyang 471023,China;School of Materials Science and Engineering,Henan University of Science and Technology,Henan Luoyang 471023,China)

机构地区：[1]高端轴承摩擦学技术与应用国家地方联合工程实验室,河南洛阳471023 [2]河南科技大学材料科学与工程学院,河南洛阳471023

出　　处：《表面技术》2024年第11期140-149,共10页Surface Technology

基　　金：国家自然科学基金(51801054);河南省科技攻关项目(222102230005);河南省重大科技专项(221100210500)。

摘　　要：目的在Ti-47Zr-5Al-3V(以下简称T47Z)表面制备TiB_(x)/Ti合金复合涂层,以提高合金的摩擦学性能。方法采用等离子弧熔覆技术在T47Z合金表面熔覆不同配比的(TiB_(2)+Ti)粉末,制备TiB_(x)陶瓷相增强钛合金复合涂层,使用扫描电镜(SEM)、X射线衍射仪(XRD)、维氏硬度显微计和UMT-2摩擦磨损试验机对涂层微观组织、硬度及摩擦磨损性能进行测试研究。结果涂层厚度约2 mm,无裂纹、气孔等缺陷,涂层的基体组织为α相,针状、棒状的TiB增强相和颗粒状的TiB_(2)增强相均匀分布于α相中。随着TiB_(2)含量的增加,涂层基体组织无明显变化,增强相的数量增加,尺寸逐渐变大。涂层的表面硬度最高可达893.4HV0.2,约为基体的2.07倍。涂层的耐磨性相较基体均获得不同程度的提升,当TiB_(2)的质量分数为40%时,涂层的耐磨性提升最为显著,相较基体提高了53.7%。T47Z合金的磨损机理为严重的黏着磨损和磨粒磨损。TiB_(2)的质量分数为10%的涂层,其磨损机理以黏着磨损为主,磨粒磨损为辅。随着TiB_(2)含量的增加,涂层的磨损机制逐渐转向磨粒磨损。结论通过控制粉体中TiB_(2)的含量,能够利用等离子弧熔覆技术在钛合金表面制备TiB_(x)/Ti合金复合涂层,尤其当TiB_(2)的质量分数为40%时,涂层的硬度及耐磨性能均获得大幅度提升。因此,运用等离子熔覆技术制备陶瓷相增强金属基复合涂层可切实有效地提高钛合金的硬度及耐磨性能。To improve the hardness and wear resistance of titanium alloy,the work aims to prepare the TiB_(x)/Ti coatings with different TiB_(2)(10%,20%,30%and 40%)contents on the surface of T47Z alloy by plasma arc cladding technology.The microstructure,mechanical properties and wear resistance of the coating were studied by scanning electron microscope,X-Ray diffractometer,Vickers hardness fiber and UMT-2 friction and wear testing machine.After cladding,the thickness of the coating was about 2 mm,and there were no cracks and pores.The substrate phase of the coating wasαphase,and the reinforcement phase was needle,rod TiB and granular TiB_(2).With the increase of TiB_(2)content in cladding powders,the matrix structure of the coating had no obvious change,and the number and size of the reinforcement phase increased gradually.It was also found that acicular TiB aggregation occurred when the content of TiB_(2)was 40%.When the content of TiB_(2)was less than 50%,the surface phase of the coating wasαphase and the reinforcement phase TiB and TiB_(2).When the TiB_(2)content reached 50%,the Ti3B4 phase was detected on the coating surface.Combined with the Ti-B phase diagram,the formation of TiB phase was discussed in detail when the content of TiB_(2)was 40%.The coating hardness was up to 893.4HV0.2,which was 2.07 times that of the substrate.The average friction coefficient of the substrate was 0.335,and the friction coefficient of the coating with 10%TiB_(2)content was 0.359 at 0-700 s.The friction coefficient of the coating decreased with the increase of TiB_(2)content.When the TiB_(2)content was 40%,the average friction coefficient of the coating was 0.312.When TiB_(2)content reached 50%,the average friction coefficient of the coating was 0.334.The COF of the coating gradually increased on the grinding.This was mainly because the soft matrix phase of the coating was constantly worn during the grinding process with the friction pair,so that more and more hard particle reinforcement phased were exposed,and the particle reinforc

关 键 词：钛合金 等离子弧熔覆 显微组织 涂层硬度 摩擦磨损性能 

分 类 号：TG174.4[金属学及工艺—金属表面处理]