超音速喷涂Cr_3C_2-25%NiCr涂层在砂粒-水环境下的磨损行为研究

Investigation on Abrasion Behaviors of Cr_3C_2-25%NiCr Coating Prepared by High Velocity Oxygen Fuel Spraying in Sand-water Environment

在模拟的砂砾-水环境下，利用滑动磨损试验研究超音速火焰喷涂（HVOF）制备的Cr3C2-25％NiCr涂层与Al2O3对磨件的摩擦磨损性能。采用扫描电镜、表面轮廓仪对涂层的磨损机理进行了分析。结果表明，随着载荷加大，磨损量呈现先略有减少后迅速增加的趋势。在高载荷下涂层磨损变得严重，主要归因于其磨损机制发生了改变，随着载荷增加，其磨损机制由微切削作用转变为裂纹扩展和剥落。同时发现不同粒径砂粒对涂层的磨损行为具有重要影响，其中280目（粒径为～140μm）砂粒与摩擦副形成协同效应，粒径减少为原始尺寸的1／3。

The wear abrasion properties of Cr3Cz-25%NiCr metal ceramic coating in water and Al2O3 sand environment were studied by sliding wear test. The coating was produced on the surface ofQ235 steel by HVOF （high velocity oxy-fuel） spraying technology. The tribological behaviors of the coating were investigated by SEM and profilometry. The results show that, with the increase of load, the abrasion mechanism converts from the micro-cutting into cracking and splat delamination; the mass loss decreases slightly first and then increases sharply; the abrasion behavior of different size of sand show significant differences. The sand of 280 mesh has synergistic effect with the sliding friction pairs, and the size of sand reduces to 1/3.