Fabrication and anti-corrosion performance of superhydrophobic silane film on sintered NdFeB
(1. College of Materials and Chemistry, China Jiliang University, Hangzhou 310018, China;
2. Department of Chemistry, Zhejiang University, Hangzhou 310027, China)
2. Department of Chemistry, Zhejiang University, Hangzhou 310027, China)
Abstract: An eco-friendly superhydrophobic protective film (DTMS/TEOS silane film) was fabricated on sintered NdFeB substrate through the utilization of electrochemically assisted deposition technology. The structure, properties, and film-forming mechanism of dodecyltrime-thoxysilane (DTMS)/tetraethoxysilane (TEOS) silane films were comprehensively analyzed using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Based on the test results, it can be determined that this film has a superhydrophobic property with a hydrophobicity angle of 152°. This special property can be attributed to the long alkyl chains in the DTMS molecule, the rough morphology, and the low surface energy of the DTMS/TEOS silane film. The surface of sintered NdFeB is coated with a layered three-dimensional network silane film that forms through the condensation of silanol substances. This film provides excellent corrosion resistance to the sintered NdFeB substrate, reducing its corrosion current density to 2.02×10-6 A/cm2. Moreover, the impact of film on the magnetic characteristics of sintered NdFeB was assessed and found to be minimal.
Key words: NdFeB magnet; silane film; corrosion resistance; superhydrophobicity; electrochemically assisted deposition