Influencing Factors on Corrosion Resistance of Nd-Fe-B Sintered Magnets Coating

来源期刊：Journal of Rare Earths2006年第S2期

论文作者：郑精武 游李顺 乔梁 姜力强

文章页码：207 - 210

摘    要：Factors that affect corrosion resistance of the protective coatings over Nd-Fe-B sintered magnets, such as microstructure of Nd-Fe-B sintered substrate, acid solutions for cleaning oxide on the magnets surfaces, etc. were investigated. Microstructure of the substrate was observed through AFM, its corrosion model was made, the bonding between the magnets and the coatings was investigated with SEM, and corrosion characteristics of Nd-Fe-B sintered substrate in some general acid solutions and in NaCl solution after coating were measured respectively through potentioynamic polarization technique. The results show that Nd-Fe-B sintered substrate has porous structure, and multi-coating is a relatively effective way to seal the pores; the oxide is eliminated more efficiently in nitric acid and vitriol, and the bonding between the magnets and the coatings is comparatively strong when the matrix is washed in vitriol; with the same thickness, corrosion resistance of the nickel-plate by electrodeposited with direct current power is stronger than by plated in other ways. By analyzing the instant model of the electroplate roller, we find that the sample was chemically eroded during the rolling process.