摘要
The electroplating pretreatment of NdFeB magnets was simulated in this study, and the effect of the pickling process on element, matrix morphology and texture was discussed. The results showed that in the ordinary circumstance the acid solution con-centration should be below 4 mol/L and the pickling time was within 120 s. However the concentration was lower than 1 mol/L and the time was about 30 s in the ultrasonic environment. The precoating technology sequentially was studied. The results revealed that there were two main reactions of the corrosion and displacement in the precoating process, and these two reactions were more obvi-ous in the grain boundary. The electrochemical analysis illustrated that the corrosion and displacement reactions were affected obvi-ously by the current density and the precoating solution temperature, usually the current density was controlled about 0.3 A/dm2, and the temperature was about 318 K in the precoating process.
The electroplating pretreatment of NdFeB magnets was simulated in this study, and the effect of the pickling process on element, matrix morphology and texture was discussed. The results showed that in the ordinary circumstance the acid solution con-centration should be below 4 mol/L and the pickling time was within 120 s. However the concentration was lower than 1 mol/L and the time was about 30 s in the ultrasonic environment. The precoating technology sequentially was studied. The results revealed that there were two main reactions of the corrosion and displacement in the precoating process, and these two reactions were more obvi-ous in the grain boundary. The electrochemical analysis illustrated that the corrosion and displacement reactions were affected obvi-ously by the current density and the precoating solution temperature, usually the current density was controlled about 0.3 A/dm2, and the temperature was about 318 K in the precoating process.
基金
supported by Zhejiang Provincial Natural Science Foundation for Youth(LQ15E010004)
Ningbo Natural Science Foundation(2014A610163)
Project of Ningbo Innovative Research Team(2012B81001)
Ningbo International Cooperation Project(2015D10019)
