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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 materials were prepared by mechanical ball milling. Ni-Cr-Ti-Al coatings with different chemical compositions were prepared on the surface of K418 Ni-based superalloy by CO2 laser. OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to investigate the bonding between the coatings and the matrix alloy. The effects of Ni, Ti and Al contents on the microstructure of the coatings were analyzed and compared. The results show that Ni2TiAl, Ni3 (Al, Ti), Ni3Ti and NiAl intermetallic phases are formed by the interaction of Ti and Al alloying elements with Ni during the cladding process. Ni-Cr-Ti- (Al, Ti) phase. The Ni2TiAl, Ni3Ti and NiAl phases are distributed between the Ni3 (Al, Ti) dendrites. Among them, the Ni66.11Cr7.35Ti14.39Al12.15 cladding layer forms TiAl The good transition of composition and properties between the alloy and K418 alloy provides a good foundation for the diffusion bonding between TiAl alloy and K418 alloy.