磁场方向对脉冲电沉积制备Ni-ZrO2 纳米复合镀层性能的影响

目的 研究有无磁场条件和垂直、平行两种磁场方向对脉冲电沉积制备Ni-ZrO2纳米复合镀层性能的影响。方法 以45#钢作为基体，采用脉冲电沉积和磁场-脉冲电沉积法成功制备Ni-ZrO2纳米复合镀层。利用扫描电镜（SEM）、能谱仪（EDS）、X射线衍射仪（XRD）、原子力显微镜（AFM）观察纳米复合镀层的表面形貌、微观结构和表面粗糙度，利用显微硬度计、划痕仪、摩擦磨损试验机对纳米复合镀层进行显微硬度、结合力和摩擦磨损性能等力学性能研究。结果 相同工艺条件下，垂直磁场-脉冲电沉积条件制备的Ni-ZrO2纳米复合镀层的晶粒形状为金子塔状，镀层表面粗糙度有所改善，复合镀层显微硬度值最高，为370HV。平行磁场-脉冲电沉积条件下制备的Ni-ZrO2纳米复合镀层表面平整，均匀致密，复合镀层中Zr的质量分数为8.27%，表面粗糙度Ra和Rq值分别为82 nm和105 nm，镀层结合力为337 N，磨损量低于其他两种镀层的磨损量。结论 施加磁场后，在磁场MHD效应作用下，纳米复合镀层表面形貌平整，均匀致密，显微硬度提高，并且与基体结合性能和耐磨性都优于无磁场条件下制备的纳米复合镀层。平行方向磁场对Ni-ZrO2纳米复合镀层的力学性能有更明显的促进作用。

Effects of Magnetic Field Direction on Properties of Ni-ZrO2 Nanocomposite Coatings Prepared by Pulse Electrodeposition

The work aims to investigate the effects of magnetic field and vertical and parallel magnetic field directions on the properties of Ni-ZrO2 nanocomposite coating prepared by pulse-electrodeposition method. Ni-ZrO2 nanocomposite coatings were prepared successfully by pulse electrodeposition (PED) and magnetic field-pulse electrodeposition (MPED) with 45# steel as the base material. The morphology, microstructure and surface roughness of Ni-ZrO2 nanocomposite coating were investigated by SEM, EDS, XRD and AFM. The mechanical properties such as microhardness, binding force and wear resistance were analyzed by the microhardness tester, scratching instrument and the friction and wear tester. Under the same process conditions, the crystal of Ni-ZrO2 nanocomposite coating prepared by the vertical MPED was in the shape of gold tower, the surface roughness was improved and the microhardness reached the maximum of 370HV. The surface of Ni-ZrO2 nanocomposite coating prepared by parallel MPED was flat, dense and uniform, the weight fraction of Zr in the composite coating was 8.27%, the surface roughness Ra and Rq values were 82 nm and 105 nm, respectively and the binding force was 337 N. Besides, the wear loss was lower than that in the other two coatings. After the magnetic field is applied, the surface of the Ni-ZrO2 nanocomposite coating is flat, uniform and dense under the MHD effects. The microhardness, binding force with the base material and wear resistance are better than PED deposited composite coating. Parallel MPED is obviously more conductive to promoting the mechanical properties of Ni-ZrO2 nanocomposite coating.