Y2O3对钛基激光熔覆层组织及性能的影响  

Effect of Y2O3 on microstructure and properties of Ti-based laser cladding layer

作　　者：张天刚 庄怀风 姚波 张倩 杨凡 ZHANG Tiangang;ZHUANG Huaifeng;YAO Bo;ZHANG Qian;YANG Fan(Engineering Technology 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：《复合材料学报》2020年第6期1390-1400,共11页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51371125);中央高校基本科研项目(3122018S004)。

摘　　要：针对Ti811钛合金硬度低、耐磨性差的问题,以TC4粉、Ni45A粉和Y2O3粉为原料,采用同轴送粉激光熔覆技术在Ti811钛合金表面进行了激光熔覆制备耐磨复合涂层的实验,分析了熔覆层的组织和相组成,测试了熔覆层的显微硬度和摩擦磨损等力学性能。研究表明:复合涂层组织由枝晶TiC、依附生长于枝晶TiC表面的纳米颗粒TiC、生长于基体表面的等轴球形(近球形)TiC、金属间化合物Ti2Ni、增强相TiB、TiB2及基体α-Ti组成,所有生成相呈均匀弥散分布状态;涂层中等轴球形(近球形)TiC和Y2O3构成了复合相结构,经二维点阵错配度计算表明,Y2O3的(111)晶面与TiC的(110)晶面的二维点阵错配度δ=6.54%,因此Y2O3可作为TiC的有效异质形核核心细化晶粒;涂层的显微硬度处于HV0.5655~700之间,较Ti811基材提高了约1.6~1.8倍;涂层的磨损机制主要为磨粒磨损,摩擦磨损性能较基材显著提升。Aiming at the problem of low hardness and poor wear resistance of Ti811 titanium alloy,the experiments of laser cladding by synchronous powder feeding laser cladding technology to prepare wear-resistant composite coatings were made.TC4 powder,Ni45A powder and Y2O3 powder were used as cladding material.The microstructure and the phase composition were analyzed.The mechanical properties of composite coating such as microhardness and friction and wear properties were tested.The research results show that the coating is made up of dendritic TiC,TiC nanoparticles grown on the surface of dendritic TiC,equiaxed spherical(nearly spherical)TiC grown on the surface of matrix,intermetallic compound Ti2Ni,reinforced phases TiB,TiB2 and matrixα-Ti.The phases are uniformly dispersed in the coating.The composite phase structure is consisted of equiaxed spherical(nearly spherical)TiC and Y2O3.The two-dimensional lattice mismatch calculation shows that the two-dimensional lattice mismatch between the(111)crystal plane of Y2O3 and the(110)crystal plane of TiC isδ=6.54%,which indicates that Y2O3 can act as the effective heterogeneous nuclei of TiC to refine grains.The microhardness is between HV0.5655 and HV0.5700,which is about 1.6 to 1.8 times higher than that of the Ti811 substrate.The wear mechanism of the coating is mainly abrasive wear,the friction and wear properties are significantly improved compared with the substrate.

关 键 词：激光熔覆 Y2O3 微观组织 二维点阵错配度 摩擦磨损 

分 类 号：TG174.44[金属学及工艺—金属表面处理]