钛合金表面自润滑陶瓷涂层的组织及耐磨性能研究  

Research on Microstructure and Wear Resistance of Self-lubricating Ceramic Coatings on Titanium Alloy

作　　者：张年龙 王波[1,2] 张红霞 戴景杰 ZHANG Nian-long;WANG Bo;ZHANG Hong-xia;DAI Jing-jie(Key Laboratory of New Metallic Functional Materials and Advanced Surface Engineering in Universities of Shandong,Qingdao Binhai University,Qingdao266555,China;School of Mechanical and Electronic Engineering,Qingdao Binhai University,Qingdao266555,China)

机构地区：[1]青岛滨海学院山东省高等学校新金属功能材料及先进表面工程重点实验室,山东青岛266555 [2]青岛滨海学院机电工程学院,山东青岛266555

出　　处：《表面技术》2018年第12期173-180,共8页Surface Technology

基　　金：山东省重点研发计划项目(2016GGX102018);山东省自然科学基金(ZR2018MEM009)~~

摘　　要：目的研究不同成分体系自润滑陶瓷涂层的耐磨性能。方法采用激光表面合金化技术,通过预置B4C和石墨混合合金化粉末的方式,在Ti-6Al-4V合金表面制备具有自润滑功能的Ti B2-Ti C陶瓷涂层,利用X射线衍射仪、扫描电子显微镜+能谱仪、维氏硬度计、摩擦磨损试验机分别分析涂层物相、组织结构、微区成分、硬度以及摩擦学特性。结果 Ti B2-Ti C自润滑陶瓷涂层无裂纹、孔洞等凝固缺陷,并与基体形成典型的冶金结合。涂层由原位生成的Ti B2和Ti C以及残留的B4C和石墨等物相组成。涂层表层由粗大、相互联结的Ti B2-Ti C联生共晶组织组成;中部和下部则由板片状、四边形、针状的Ti B2,弥散的Ti B2-Ti C联生共晶组织以及树枝状和颗粒状Ti C等组成。由于多相陶瓷的协同作用,涂层的最高硬度可达2167HV,其平均硬度为基体的4.7～5.3倍。由于陶瓷较高的硬度和残留石墨良好的润滑性,涂层的摩擦系数和磨损率分别仅为基体的2/5～1/2和1/20.1～1/25.7。原始合金粉末B4C∶C=2∶1(摩尔比)的涂层(2-1涂层)具有最低的体积磨损率。结论 Ti B2-Ti C自润滑陶瓷涂层具有良好的减摩和耐磨性能。由于高的硬度和良好的减摩性,2-1涂层具有最好的抗磨损性能。The work aims to investigate the wear resistance of the self-lubricating coatings with different composition system.TiB2-TiC self-lubricating ceramic composite coatings were fabricated on Ti-6Al-4V alloy by laser surface alloying with the powders of B4C and graphite.Phase of the coatings was analyzed by X-ray diffractometer.Microstructure of the coatings was observed by scanning electron microscope.Chemical composition of micro-area of the coatings was analyzed by energy dispersive spectroscope.Hardness of the coatings was measured by Vickers hardness tester.Tribological characteristics of the coatings were tested by friction and wear tester.The results show that the coatings were free of cracks and pores and exhibited good metallurgical bonding with the substrate.The coatings were composed of the in-situ formed phases of TiB2 and TiC and the residual phases of B4C and graphite.The upper zone of the coatings was comprised of coarse and interlinked TiB2-TiC epitaxial microstructure.The middle and bottom zone of the coatings were comprised of plate-like,quadrilateral and acicular TiB2,dispersed TiB2-TiC epitaxial eutectic microstructure,and dendritic and granular TiC.The maximum hardness of the coatings was 2167HV,and the average hardness of the coatings was equivalent to 4.7~5.3 times of the substrate.Due to the lubrication of residual graphite and high hardness of the ceramic phases,the minimum friction coefficient of the coatings was about 1/2 of the substrate and the minimum wear volume of the coatings was about 1/25.7 of the substrate.The coating with the original alloying powders B4C∶C=2∶1(mole ratio,2-1 coating)had the lowest wear volume.TiB2-TiC self-lubricating ceramic composite coatings possessed good friction-reducing property and wear resistance.Due to the highest hardness and good friction-reducing effect,2-1 coating had the best wear resistance.

关 键 词：钛合金 激光表面合金化 TiB2-TiC陶瓷涂层 自润滑 耐磨性能 

分 类 号：TG174.4[金属学及工艺—金属表面处理]