Microstructure and corrosion resistance of Zn–Al/T8 superhydrophobic composite coating on sintered NdFeB magnet
X.H. Zhang, Junming Luo, J.L. Xu, Jin Chen, Jun Huang, Yongcun Ma, Mingshan Xue
Abstract
In order to improve the corrosion resistance, the Zn–Al/T8 (2-perfluorooctane ethyl acrylate) super- hydrophobic composite coating was prepared on the sintered NdFeB magnet by spin coating method coupled with plasma-enhanced chemical vapor deposition. The results show that the Zn–Al coating is mainly composed of lamellar Zn and Al phases with the thickness of approximately 28 μm. The contact angle of the Zn–Al/T8 coating reaches 151.78° with the rolling angle of 5.13°, indicating that the Zn–Al/T8 coating can provide a superhydrophobic surface. The Zn–Al and Zn–Al/T8 coatings have no significant effect on the magnetic properties of the NdFeB magnets. The Zn–Al coating improves the corrosion resistance of the NdFeB by sacrificing the anode, while the Zn–Al/T8 coating further enhances the corrosion resistance through the superhydrophobic surface. The Zn–Al/T8 composite coating has better salt spray resistance than Zn–Al coating. The Zn–Al/T8 superhydrophobic composite coating is a promising candidate for protecting the sintered NdFeB magnets.