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采用激光熔覆技术,在45#钢表面制备原位生成WB-CrB颗粒增强镍基复合涂层。使用X射线衍射仪(XRD)、金相显微镜、扫描电镜(SEM)和能量色散谱(EDS),对熔覆层的显微组织和物相构成进行分析,并对硬度、摩擦性能进行测试。结果表明,在适当工艺条件下,原位生成WB-CrB颗粒增强镍基涂层形貌良好,涂层与基材呈冶金结合。熔覆层底部组织为定向生长的γ(NiFe)树枝晶,熔覆层中上部组织为WB-CrB颗粒相,均匀分布于γ(NiFe)树枝晶基体中。熔覆层具有较高的硬度(平均硬度HV0.31350)和良好的耐磨性,其摩损失重仅为纯Ni60熔覆层的1/7。大量WB-CrB复合颗粒的形成及其在涂层中的均匀弥散分布是熔覆层硬度和耐磨性提高的主要原因。
WB-CrB particle reinforced nickel-based composite coating was prepared in-situ on 45 # steel by laser cladding. The microstructure and phase composition of the coating were analyzed by X-ray diffraction (XRD), optical microscope, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The hardness and tribological properties were also tested. The results show that the morphology of in-situ WB-CrB particles reinforced nickel-based coatings is good and the coating is metallurgically bonded with the substrate under proper conditions. The microstructure of the cladding layer is oriented growth of γ (NiFe) dendrites. The upper microstructure of the cladding layer is WB-CrB particles and uniformly distributed in the γ (NiFe) dendrite matrix. The cladding has a high hardness (average hardness HV0.31350) and good wear resistance, the wear loss is only 1/7 of the pure Ni60 cladding. The formation of a large number of WB-CrB composite particles and its uniform dispersion in the coating distribution of the coating hardness and wear resistance is the main reason.