LaF_3对激光原位合成TiC组织与性能影响

Influences of LaF_3 on microstructure and performance of laser cladding layer in-situ fabricated

利用激光熔覆技术原位合成添加稀土LaF3的TiC/Ni复合涂层.借助于电子探针(EPMA)、透射电镜(TEM)、扫描电镜(SEM)、显微硬度计、M—2000摩擦磨损试验机、M398电化学腐蚀系统对涂层组织结构、元素分布、硬度及耐磨、耐蚀性能进行了分析.结果表明,添加适量稀土LaF3,可改善组织均匀性,细化晶粒,TiC颗粒偏聚减轻,异质相含量降低,LaF3含量为1%时熔覆层硬度最高,LaF3含量为2%时熔覆层耐磨及耐蚀性较高.添加过量稀土LaF3后,异质相含量增加,TiC颗粒偏聚,熔覆层硬度降低,使耐磨性和耐蚀性降低.

In-situ Ni-based TiC composite coatings with LaF3 were made by laser cladding,and the microstructure,composition profiles,microhardness,wear and corrosion properties of the coatings were analyzed by using electron probe micro-analyzer (EPMA),transmission electron microscope (TEM),scanning electron microscope (SEM),microhardness instrument,M-2000 Friction and Wear Tester,and M398 Electrochemical corrosion systems.The results show that after adding moderate rare earth LaF3,the microstructure presents more homogeneous,the fineness of grain becomes finer,TiC distributes better and heterogeneous phase decreases.When the content of LaF3 is 1%,the highest microhardness is got; when it is 2%,the optimal wear and corrosion resistance properties are obtained; but when adding excessive rare earth LaF3,both the microstructure and properties will get worse.