烧结钕铁硼表面复合电沉积氧化石墨烯镀锌层

目的烧结钕铁硼(NbFeB)是一种应用范围非常广泛的多孔磁性材料,由于多孔结构易发生腐蚀,需在其表面制备相应的镀层进行防护。方法利用电沉积法将提前制备的氧化石墨烯(GO)与镀锌溶液混合,在NdFeB基体表面电沉积制备出锌镀层与氧化石墨烯复合镀锌层。结果镀锌液中,氧化石墨烯(GO)的浓度、阴极电流密度以及搅拌速度,对复合镀锌层的表面微观形貌具有一定的影响,同时一定浓度的氧化石墨烯(GO)可以改变镀层的生长取向,Zn/rGO的优先生长晶面由(100)变成(002)。膜层的微观形貌从纯锌紧密堆积在一起的凸起晶粒变成了Zn/rGO的纳米片状形貌。交流阻抗和动电位极化曲线结果表明,镀Zn层和Zn/rGO复合镀锌层经过3.5%Na Cl溶液中浸泡后,Zn/rGO纳米复合镀层的耐腐蚀性能明显增加。结论相比于单一的镀锌层,Zn/GO复合镀锌层的耐腐蚀性明显增加。

Preparation of Graphene Oxide Zinc Composite Coating on Sintered NbFeB by Electrodeposition

NbFeB is a kind of widely used magnetic material, since porous structure is easily corroded, corresponding coatings shall be prepared on the surface for protection. Nano-sized graphene oxide (GO) prepared in advance was mixed with galvanizing solution to prepare zinc coating and Zn-GO composite coating on NbFeB surface. Concentration, cathode-current density and stirring rate had certain effects on surface morphology of the composite zinc coating. Meanwhile, growth orientation of the coating could be altered by the graphene oxide (GO) of certain concentration, preferential growth crystal face transformed from (100) to (002). Morphology of the coating transformed from bulged grain tightly accumulated by pure zinc into Zn/rGO nanosheet-like morphology. According to AC independence and potential polarization curve, corrosion resistance of Zn/rGO nano composite coating increased significantly after the Zn coating and Zn/rGO composite coating were soaked in 3.5%NaCl solution. Compared with single Zn coating, the corrosion resistance of the Zn/GO composite coating increases obviously.