钛基稀土激光熔覆层组织细化机制及性能  

Microstructure refinement mechanism and properties of Ti-based rare earth laser cladding layers

作　　者：张天刚 庄怀风 薛鹏 张倩 姚波 李宝轩 ZHANG Tiangang;ZHUANG Huaifeng;XUE Peng;ZHANG Qian;YAO Bo;LI Baoxuan(Engineering Techniques Training Center,Civil Aviation University of China,Tianjin 300300,China;Sino-European Institute of Aviation Engineering,Civil Aviation University of China,Tianjin 300300,China;College of Aeronautical Engineering,Civil Aviation University of China,Tianjin 300300,China)

机构地区：[1]中国民航大学工程技术训练中心,天津300300 [2]中国民航大学中欧航空工程师学院,天津300300 [3]中国民航大学航空工程学院,天津300300

出　　处：《航空学报》2020年第9期329-342,共14页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(51371125);中央高校基本科研业务费专项资金(3122018D013)。

摘　　要：采用通快TruDisk 4002光纤激光器在TC4合金表面分别制备了0wt%Y2O3和3wt%Y2O3的TC4+Ni45+Co-WC钛基耐磨复合涂层。利用XRD、SEM、EDS、EPMA、显微硬度计和摩擦磨损试验机等分析了涂层组织、显微硬度和摩擦学性能。结果表明,两种涂层表面均无裂纹孔隙等缺陷,且生成相一致,主要包括TiC、TiB2、Ti2Ni、WC和α-Ti;0wt%Y2O3涂层组织存在明显偏析,析出相尺寸粗大且方向性明显;3wt%Y2O3涂层组织呈均匀弥散状态分布,细化特征明显;经Bramfitt二维点阵错配度计算,(100)Y2O3和(100)Ti2Ni、(111)Y2O3和(110)TiC、(110)Y2O3和(1010)TiB2间的错配度分别为5.75%、6.72%和10.10%,Y2O3作为异质形核核心对Ti2Ni、TiC和TiB2的细化能力依次为Ti2Ni>TiC>TiB2;0wt%Y2O3和3wt%Y2O3涂层显微硬度分别为600~630HV0.5和470~480HV0.5,较基材分别提高了约62%和26%;3wt%Y2O3涂层耐磨减摩性最优,其磨损体积和摩擦系数较0wt%Y2O3涂层分别下降了约47.8%和5.0%,磨损机制主要为磨粒磨损。TC4+Ni45+Co-WC Ti-based wear-resistant composite coatings with different Y2O3 additions(0wt%and 3wt%)were prepared on the surface of TC4 alloy by using TRUMPF TruDisk 4002 fiber laser.The microstructure,microhardness,and tribological properties of the coatings were analyzed by using XRD,SEM,EDS,EPMA,microhardness tester,and friction and wear apparatus.The results show that there are no cracks,pores,and other defects on the two coating surfaces,and the formation phases are consistent,mainly including TiC,TiB2,Ti2Ni,WC andα-Ti.In 0wt%Y2O3 coating,there is an obvious microstructure segregation and the size of the precipitated phase is coarse with the evident dendrite orientation.In 3wt%Y2O3 coating,the microstructure is uniformly dispersed and the refinement effect is significant.According to Bramfitt two-dimensional lattice misfit calculation,the misfit between(100)Y2O3and(100)Ti2Ni,(111)Y2O3and(110)TiC,and(110)Y2O3and(1010)TiB2are 5.75%,6.72%and 10.10%,respectively.The ability of Y2O3acting as an effective heterogeneous nucleus to refine Ti2Ni,TiC and TiB2is Ti2Ni>TiC>TiB2.The microhardness of 0wt%Y2O3 coating and 3wt%Y2O3 coating is 600-630HV0.5 and 470-480HV0.5,which is 62%and 26%higher than that of the substrate.3wt%Y2O3coating shows the best wear resistance and anti-friction.The wear volume and friction coefficient are 47.8%and 5.0%lower than those of 0wt%Y2O3 coating,and the wear mechanism is mainly abrasive wear.

关 键 词：Y2O3 TC4 激光熔覆 二维点阵错配度 微观组织 摩擦磨损 

分 类 号：V252[一般工业技术—材料科学与工程]