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以镍包铝、镍基自熔性合金以及铝的混合粉为原料,利用激光工艺与镍、铝之间的反应合成相结合,制备了Ni-Al金属间化合物涂层。实验结果表明,涂层显微组织主要由NiAl和Ni3Al两相构成,其中NiAl相呈树枝晶形貌,Ni3Al相有两种形态,一种沿NiAl树枝晶间呈连续网状分布,另一种在NiAl相上析出,呈细小不规则角状。与直接熔覆镍包铝相比,镍包铝中添加镍基合金与铝后,多道熔覆功率由2.4 kW下降为2.1 kW,涂层质量改善,同时降低了基底中铁元素的熔入;涂层硬度由410~440 HV提高到490~540 HV。
Ni-Al intermetallic compound coating was prepared by the combination of nickel-clad aluminum, nickel-based self-fluxing alloy and aluminum mixed powder by the laser reaction between nickel and aluminum. The experimental results show that the coating microstructure mainly consists of NiAl and Ni3Al two phases, in which the NiAl phase dendritic morphology, Ni3Al phase has two forms, one along the NiAl dendrites was continuously reticular distribution, the other Precipitation in the NiAl phase, was small irregular horn. Compared with direct cladding of nickel clad aluminum, the addition of nickel base alloy and aluminum to nickel clad aluminum reduced the power of multipass cladding from 2.4 kW to 2.1 kW, improved the coating quality and reduced the infiltration of iron in the substrate. Coating hardness increased from 410 ~ 440 HV to 490 ~ 540 HV.