烧结NdFeB表面铜-石墨烯复合膜的制备与表征

Preparation and Characterization of Copper-Graphene Com-posite Films on Sintered NdFeB Surface

摘要:

采用电沉积铜-石墨烯（Cu-GR）复合膜的方法对稀土永磁NdFeB材料进行包覆以提高其耐腐蚀性。对Cu-GR膜层的微观结构、水接触角和表面显微硬度等方面进行了分析。结果表明，随着电沉积液中石墨烯的添加量从0 g·L^-1增加到0.9 g·L^-1，膜层的疏水性和硬度随之提高。通过SEM/EDS和XPS表征，验证了石墨烯在Cu-GR膜层中的均匀分散以及Cu-GR复合材料的组成。利用动电位极化曲线和电化学阻抗谱（EIS）研究了Cu-GR复合镀层的电化学性能。结果表明，石墨烯的加入使膜层的电化学性能更加稳定、耐蚀性得到提高。当电沉积液中石墨烯添加浓度为0.3 g·L^-1时，获得的Cu-GR复合包覆层在NdFeB基体上表现出最优的综合保护效果。

Abstract:

Corrosion resistance of rare earth permanent magnet material NdFeB was achieved by electrodeposited Cu-graphene (Cu-GR) composite films. The impact of the films on corrosion performances was studied by examining the morphology, water contact angle, and surface microhardness. The results show that the hydrophobicity and the hardness are enhanced as the concentration of graphene in the plating solution increases from 0 g·L^-1 to 0.9 g·L^-1. The characterization through SEM/EDS and XPS verifies the uniform dispersion of graphene sheets in the electrodeposited coating and the composition of Cu-GR composites. The electrochemical performance of the Cu-GR composite coating was investigated by potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS), and it is demonstrated that the electrochemical performance becomes more stable and the corrosion resistance is improved with the addition of graphene in the composites. For the sintered NdFeB samples coated with Cu-GR composite films with different graphene concentrations the best protective effect is obtained for the film prepared from the plating solution with a graphene concentration of 0.3 g·L^-1.