(安徽工业大学 材料科学与工程学院， 马鞍山 243002)
摘 要: 应用光学显微镜、 扫描电镜(SEM)、 X射线衍射(XRD)、 透射电镜(TEM)以及滑动磨损实验， 研究不同Mo加入量对等离子熔覆镍基合金涂层组织结构和性能的影响。 结果表明， 熔覆层主要是由面心立方结构的γ(Ni, Fe)固溶体、 六方结构的M7(C, B)3和四方结构的Cr2B等物相构成， 在镍基固溶体中存在明显的成分偏析。 Mo的加入没有改变熔覆层的相结构， 但硼碳化物的相对含量却有所提高， 成分偏析逐渐减弱， 直至消失， 并且促进了等轴晶的形成。 Mo的加入可以提高熔覆层的耐磨性能， 当其加入量在6%以内时， 随着Mo加入量的提高， 熔覆层的耐磨性逐渐提高。 但是， 当加入量达到8%时， 耐磨性能开始降低。
关键字: 等离子熔覆； 镍基合金； 钼； 组织结构； 耐磨性
（School of Materials Science and Engineering, Anhui University of Technology, Ma'anshan 243002, China）
Abstract: The effect of different Mo additions on the microstructure and wear resistance of the nickel-based alloy coating produced by plasma cladding was investigated using optical microscope, scanning electron microscope (SEM), X-ray diffraction (XRD), transmission electron microscope (TEM), and sliding wear test. The results show that the γ(Ni, Fe) solid solution with a face-centered cubic crystal structure is presented accompanied by the M7(C, B)3 with a hexagonal crystal structure and Cr2B with a tetragonal crystal structure in the nickel-based alloy coating. The obvious component segregation exists in the nickel-based solid solution. The addition of Mo does not change the phase composition, though the relative content of boride and carbide increases. Meanwhile, the component segregation decreases gradually then disappears finally with the increasing Mo content. The equiaxed crystals come into being in the Mo-modified coating. The addition of Mo increases the wear resistance. The wear resistance increases with the increasing Mo content when its content is lower than or equals to 6%. On the contrary, the wear resistance decreases again when the Mo content equals to 8%. The addition of Mo can homogenize the component, promote the formation of equiaxed crystals, and increase the relative quantity of boride and carbide. All these results are beneficial to increasing the wear resistance of the cladding coating.
Key words: plasma cladding; nickel-based alloy; Mo; microstructure; wear resistance
