K418合金激光熔覆Ni-Cr-Ti-Al涂层的组织研究  

Microstructures of Ni-Cr-Ti-Al Laser Claddings on K418 Superalloy

作　　者：罗根香[1] 吴国清[1] 黄正[1] 阮中健[1] 

机构地区：[1]北京航空航天大学材料科学与工程学院,北京100083

出　　处：《中国激光》2007年第2期283-287,共5页Chinese Journal of Lasers

基　　金：航空基础科学基金(01H51004);哈尔滨工业大学现代焊接生产技术国家重点实验室基金(2002-3)资助项目

摘　　要：采用机械球磨法获得混合均匀的Ni-Cr-Ti-Al熔覆材料;并利用CO2激光器在K418镍基高温合金表面制备了不同化学成分的Ni-Cr-Ti-Al涂层;采用光学显微镜(OM)、扫描电子显微镜(SEM)及X射线衍射仪(XRD)等手段探讨了不同成分涂层与基体合金的结合情况。分析比较了Ni,Ti和Al含量对熔覆涂层的组织特征的影响。结果表明,在熔覆过程中,Ti,Al合金元素与Ni相互作用将形成Ni2TiAl,Ni3(Al,Ti),Ni3Ti和NiAl金属间化合物相;Ni-Cr-Ti-Al熔覆涂层以Ni3(Al,Ti)相形成的枝晶组织为主,Ni2TiAl,Ni3Ti及NiAl相分布在Ni3(Al,Ti)枝晶间;其中,Ni66.11Cr7.35Ti14.39Al12.15熔覆涂层形成了TiAl合金与K418合金之间成分和性能的良好过渡,为实现TiAl合金/K418合金异种合金间的扩散连接提供了良好的组织基础。Ni Cr-Ti-Al cladding powders were mixed by using mechanical ball milling technique. Ni-Cr-Ti-Al laser cladding layers with different chemical composition on superalloy K418 were prepared by CO2 laser. By means of optical microscopy （OM）, scan electron microscopy （SEM） and X-ray diffraction （XRD）, microstructures of cladding layers were studied, and micro-hardness was measured. The results show that, during the process of laser cladding, Ni3 （Al, Ti）, Ni2TiAl, NiAl and Ni3 Ti intermetallic compounds are formed resulting from the interaction of Ti, Al and Ni. Microstructures of Ni-Cr-Ti-Al cladding layers are characterized by massive Ni2TiAl, Ni3 Ti or NiAl distributing between Ni3 （Al,Ti） dendritic. Ni-Cr-Ti-Al laser cladding layer with the chemical composition of Ni66. 11Cr7.35Ti14.39Al12.15 is beneficial to the diffusion bonding between TiAl alloy and K418 superalloy.

关 键 词：激光技术 激光熔覆 镍基高温合金 TIAL合金 显微组织 

分 类 号：TG156.99[金属学及工艺—热处理]