钛对激光熔覆Ni_3Si金属间化合物涂层的影响  

Effect of Ti Addition on Microstructural Evolution of Ni_3Si Laser Clad Coatings

作　　者：孙耀宁[1] 程康娜 孙文磊[1] 张建斌[2] 

机构地区：[1]新疆大学机械工程学院,乌鲁木齐830047 [2]兰州理工大学材料科学与工程学院,兰州730050

出　　处：《有色金属工程》2015年第5期11-13,54,共4页Nonferrous Metals Engineering

基　　金：国家自然科学基金资助项目(51465055)

摘　　要：利用激光熔覆技术合成Ni3Si涂层修复改善高温合金的使用性能,添加合金化元素改善Ni3Si的脆性问题。以镍、硅、钛元素粉末为原料,利用10 k W CO2连续激光器在GH864表面激光熔覆制备Ni-Si金属硅化物复合材料涂层。采用扫描电子显微镜、X射线衍射和显微硬度计表征熔覆试样的微观组织、相组成和显微硬度。结果表明,熔覆层组织主要由镍固溶体、Ni3Si和Ni3 1Si12组成,随着钛含量的增加涂层组织为镍固溶体和Ni3(Si,Ti)。熔覆层的平均硬度随钛含量的增加而减小,主要是因为钛的添加减小了涂层组织中硬质相的含量。随着钛含量从0增加到9%,涂层合金晶格常数从0.351 00 nm增加到0.353 18 nm。The performance of high temperature alloy is improved by Ni3 Si intermetallic coating formed with laser cladding technique, and the brittleness of Ni3Si is adjusted by addition of the alloying element Ti. The Ni-Si metallic silieide coatings are prepared with Ni, Si and Ti powder on the GH864 material surface by 10 kW CO2 continuous laser. The microstructure, phase composition and microhardness of the specimens are characterized by using X-ray diffraction （XRD） , scanning electron microscopy （SEM） and energy dispersive x-ray spectroscopy （EDS）. The results show that the microstrueture of the coating specimens consists of nickel solid solution, Ni3Si and Ni31Si12. With the increase of the Ti content, the phase composition of the coating microstructure becomes to nickel solid solution and Ni3 （Si, Ti）. The average hardness of the coating is decreased with the increase of the Ti content, mainly reason is the hard phase content is decreased. As Ti content is increased from 0 to 9% , lattice constant of the coating alloy is increased from 0. 351 00 nm to 0. 353 18 nm.

关 键 词：激光熔覆 金属间化合物 合金化 显微组织 

分 类 号：TG174.44[金属学及工艺—金属表面处理]