Current Status and Challenges in Corrosion and Protection Strategies for Sintered NdFeB Magnets

The susceptibility of sintered NdFeB to corrosion in harsh environments limits their wide variety of applications. Improved resistance to corrosion of NdFeB magnets and advancement of surface coatings are critical directions in permanent magnet material fields. Significant work has been undertaken on the development of long-life NdFeB magnets. However, comprehensive research of NdFeB corrosion, from process technology to fundamental theory, is lacking, mainly owing to the hysteresis in the study of the elementary works of corrosion and protection related to magnetism, and improving the quality and diversified market demands. This analysis covers recent research that has led to advances in anticorrosion material technology for NdFeB magnets, including corrosion factors, contemporary methodologies from technology to fundamentals, the basic framework for surface protection and key techniques in the industry application. Finally, prospects and existing challenges in the field of corrosion and protection are reviewed, attempting to identify future developments and directions.