Abstract
The poor corrosion resistance restricts the industrial applications of nanocrystalline soft magnetic Fe-Zr-B alloys.We reported a facile plasma-nitriding surface process to enhance the corrosion resistance of a nanocrystalline Fe90Zr7B3 alloy without deteriorating its soft magnetic properties.Potentiodynamic po-larization and electrochemical impedance spectroscopy were performed to investigate the corrosion be-havior.The nitrided alloy shows higher corrosion resistance than the untreated alloy,as evidenced by a nobler corrosion potential,lower corrosion current and higher polarization resistance of surface corrosion film,while their magnetic properties are similar.The microstructures of both nanocrystalline alloys were examined by high-resolution transmission electron microscopy(HRTEM)and the compositions of their corrosion films analyzed by X-ray photoelectron spectroscopy(XPS).For the nitrided alloy,a more homo-geneous nanocrystalline structure developed in the surface nitrided layer containing corrosion-resistant nitride phases(Fe3N and ZrN)provides a higher resistance against chloride corrosion.Moreover,the ni-trided layer facilitates the formation of a more protective corrosion film with the increased ratios of Fe2+/Fe3+and O2-/OH-as well as higher enrichment of Zr-and B-oxides,while the N-species(NH4+and NO3-)formed in the corrosion film behave as good corrosion inhibitors and further enhance the film pro-tection.Our findings provide a simple strategy for the preparation of corrosion-resistant nanocrystalline soft magnetic alloys to satisfy a variety of engineering requirements.
基金项目
National Natural Science Foundation of China(51771215)
National Natural Science Foundation of China(51701038)
National Natural Science Foundation of China(51974091)
Natural Science Foundation of Liaoning Provincial Department of Science and Technology(2021-MS-308)
Fundamental Research Funds for the Central Universities(N2125009)