Amorphous Al-Mn coating on NdFeB magnets: Electrodeposition from AlCl3-EMIC-MnCl2 ionic liquid and its corrosion behavior

作者：Chen, Jing; Xu, Bajin; Ling, Guoping^*

来源：Materials Chemistry and Physics, 2012, 134(2-3): 1067-1071.

DOI：10.1016/j.matchemphys.2012.03.114

• NdFeB
• Al-Mn amorphous coating
• Electrolytic etching
• Anodic coating

Amorphous Al-Mn coating was electrodeposited on NdFeB magnets from AlCl3-EMIC-MnCl2 ionic liquid with the pretreatment of anodic electrolytic etching in AlCl3-EMIC ionic liquid at room temperature. The microstructure, composition and phase constituents of the coatings were investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The corrosion resistance of the coatings was tested by means of potentiodynamic polarization and immersion test in 3.5 wt. % NaCl solution. The results show that anodic electrolytic etching in AlCl3-EMIC ionic liquid is a satisfactory pretreatment to remove the surface oxide film and favor the adhesion of the Al-Mn alloy coating to the NdFeB substrate. The amorphous Al-Mn alloy coating provides sacrificial anodic protection for NdFeB. It exhibited good corrosion resistance and significantly reduced the corrosion current density of NdFeB by three orders of magnitude at potentiodynamic polarization.

• 出版日期2012-6-15
• 单位浙江大学