Densification and anticorrosion performances of vacuum evaporated aluminium coatings on NdFeB magnets

• 作者: Jun Huang Qing Liu Zhenyu Yang Guangqing Xu Pengjie Zhang Jun Lv Wei Sun Bingshan Li Dongmei Wang Yucheng Wu
• 来源期刊: 稀土学报（英文版）
• 年，卷（期）: 2021,（10）
• 所属期刊栏目: MAGNETISM AND MAGNETIC MATERIALS
• 页码范围: 1238-1245
• 页数: 8页
• 语种: 英文

摘要

Al coated NdFeB magnets obtained by vacuum evaporation technique were densified by high energy ball milling method.The surface morphology,metal composition and microstructure of the coatings were characterized by scanning electron microscopy,X-ray diffraction and X-ray photoelectron spectroscopy,respectively.The anticorrosive properties were investigated by potentiodynamic polarization curves and neutral salt spray test.The pores in the Al coatings of columnar crystals (Al) induced by the evaporation technique,were apparently filled in the following ball milling process,leading to the densification of Al coatings and the evident improvement of the anticorrosive performances.When treated with ball milling for 30 min,the sample achieves the best anticorrosive performances with the self-corrosion potential of-0.87 V,self-corrosion current density of 1.65μA/cm2 and the neutral salt spray (NSS) time of 144 h(red rust).The improvement of the anticorrosive performances of vacuum evaporated Al coating mainly lies in the densification effect of the coating,which depends on different loading conditions of ball milling process.