LaF_3对激光原位合成TiC组织与性能影响

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.

Influences of LaF3 on microstructure and performance of laser cladding layer in-situ fabricated

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.