钕铁硼稀土永磁材料室温熔盐电镀铝的研究

在钕铁硼(NdFeB)稀土材料表面直接进行水溶液电镀时,存在镀层分层、易起泡等缺陷.采用AlCl3/EMIC(1-甲基-3-乙基氯化咪唑)室温熔盐电解质在NdFeB永磁材料表面电镀铝,是提高其表面防护质量的有效方法.探讨了NdFeB永磁材料在室温熔盐中电镀铝的可行性、熔盐配比和芳香化合物对电镀铝层组织形态的影响,同时对镀层形成的机理进行了初步探讨.研究表明:采用AlCl3/EMIC室温熔盐电解质可在NdFeB永磁材料表面获得满意的铝镀层;铝镀层纯度很高,较完整平滑;添加芳香化合物可以大大提高镀层的质量,使晶粒细小、致密.

Electroplating of Aluminum on NdFeB Magnet in AlCl3/ EMIC Molten Salt at Ambient Temperature

The electroplating of NdFeB rare earth material in aqueous solution has the disadvantage of plating delaminating and blistering. Such a disadvantage could be overcome in the electroplating of aluminum on NdFeB permanent magnetic material in molten salt electrolyte AlCl_ 3/EMIC (1-methyl-3-ethyl-imidazole chloride) at room temperature.Thus the process for the electroplating of aluminum on NdFeB permanent magnetic material in the molten salt electrolyte at room temperature was investigated.The effects of the AlCl_ 3/EMIC molten salt composition and aromatic compound on the structure of the aluminum plating were explored,and the formation mechanism of the Al plating was discussed.As the results,it was feasible to electroplate aluminum on the NdFeB magnet in the molten salt electrolyte at ambient temperature.The resulting Al electroplating had good quality, which was confirmed by the relevant energy dispersive spectrometric analysis.The aluminum coating on the NdFeB magnet surface deposited from the molten salt electrolyte of an AlCl_ 3/EMIC mole ratio of 65/35 was compact and smooth.Moreover,the aromatic compound contributed to increasing the adhesion to substrate and compactness of the Al plating,and enhancing the refining of the crystal grain as well.