碳化铬／铁基自熔合金复合涂层真空反应钎涂

Chromium carbide/Fe-based self-fluxing alloy composite coatings produced by vacuum reactive braze coating

以纯铁粉、硅粉、硼铁粉、铬铁粉、胶体石墨及镍粉为原料,通过真空反应钎涂在低碳钢基体上制备了碳化铬／铁基自熔合金复合涂层,涂层表面光滑、平整且与基体为冶金结合。应用扫描电子显微镜、能谱仪、X射线衍射仪及显微硬度计,研究了涂层的组织结构、成分分布和硬度分布。结果表明：涂层为复合结构,其组织由Fe-Ni固溶体基底和原位合成的六棱柱Cr_3C_2相组成。涂层与基体间存在过渡区,过渡区内元素和硬度呈梯度分布；涂层表面硬度可达85HR15N以上。

Using carbon, iron, silicon, ferrochromium, ferrotitanium and nickel powder as the raw materials, chromium carbide/Fe-based composite coatings with an even and smooth surface were prepared by vacuum reactive braze coating, which combined with a mild steel substrate by a metallurgical bonding. The phase structure, composition distribution and hardness distribution of the coatings were studied by means of scanning electron microscopy （SEM）, energy dispersive spectrum （EDS）, X-ray diffraction （XRD） and microhardness testing. The results showed that the coating had a composite structure, and the microstructure of the coating consists of an Fe-Ni solid solution matrix and in-situ synthesized hexagon prismy Cr3C2. There was a transition zone between the coating and the substrate, in which chemical elements and microhardness had a gradient distribution. The surface hardness of the composite coating was high up to 85HR15N.