TC4钛合金表面激光熔覆掺Y_2O_3复合涂层的显微组织和性能  

Microstructure and Properties of Y_2O_3-doped Laser Cladded Composite Coating on TC4 Titanium Alloy

作　　者：马永[1] 朱红梅[1] 孙楚光[1] 廖帮亮 申龙章[1] 何彬[1] 朱卫华[2] 王新林[1,2] 

机构地区：[1]南华大学机械工程学院,湖南衡阳421001 [2]南华大学电气工程学院,湖南衡阳421001

出　　处：《表面技术》2017年第6期238-243,共6页Surface Technology

基　　金：湖南省自然科学基金(2015JJ6098)~~

摘　　要：目的提高钛合金表面的耐磨性能。方法在TiB_2:TiC=1:3的粉末配比下,添加不同质量分数Y_2O_3稀土氧化物,制备成膏状混合粉末。采用5 k W横流CO_2激光器,在TC4钛合金表面激光熔覆掺Y_2O_3的TiB_2和TiC粉末,制备耐磨性复合涂层。通过扫描电子显微镜(SEM)、X射线能谱仪(EDS)、X射线衍射仪(XRD)对激光熔覆层的微观形貌和组织成分进行了分析;用显微维氏硬度计对熔覆层的显微硬度进行了测量;用万能摩擦磨损试验机对熔覆层的耐磨性能进行了测试。结果添加4%Y_2O_3后,熔覆层中部组织明显细化,结合区由致密组织结构转变为晶须网状结构;熔覆层的最高显微硬度为1404.6HV0.2,是基体的3.7倍;熔覆层的磨损量减少了66.67%,且其摩擦系数有明显的降低。结论添加4%Y_2O_3对TC4钛合金表面激光熔覆TiB/TiC复合熔覆层耐磨性能有显著的提高。The work aims to improve wear resistance of TC4 titanium alloy. Pasty mixed powder was prepared at a proper ratio of TiB2：TiC （1：3） and adding Y2O3 rare earth oxide in different mass fractions. Wear resistant composite coating was pre- pared by laser cladding Y2O3-doped TiB2 and TiC powder on the surface of TC4 titanium alloy using 5 kW continuous wave CO2 laser. Microstructure and composition of the laser cladding layers were analyzed with scanning electron microscope （SEM）, energy dispersive spectrometer （EDS） and X-ray diffractometer （XRD）; microhardness of the laser cladding layer was measured with Vickers hardness tester; and wear resistance was tested with universal friction and wear tester. After 4% Y2O3 was added,grain size of the middle structure was greatly refined; microstructure of the bonding zone was transformed from compact struc- ture to reticular whisker structure; maximum microhardness of the cladding layer was 1404.6HV0.2, 3.7 times as high as that of TC4 substrate; wear loss of the cladding layer decreased by 66.67%, and the friction coefficient decreased remarkably. Wear re- sistance of the laser cladded TiC/TiB composite cladding coating on the surface of TC4 titanium alloy can be improved signifi- cantly by adding 4% Y2O3.

关 键 词：TC4钛合金 激光熔覆 复合涂层 显微组织 显微硬度 耐磨性能 

分 类 号：TG174.44[金属学及工艺—金属表面处理] TN249[金属学及工艺—金属学]