New Achievements in NdFeB Mass Production

It shows the latest achievements of sintered NdFeB magnet on the manufacturing techniques and the coating techniques of China, through the comparison between those achievements and the advanced techniques on the world. The control of oxygen content has the priority in the high performance NdFeB manufacturing. Yantai Zhenghai Magnetic Materials Co., Ltd. realized Zhenghai Oxygen-Free Process (ZHOFP) in sintered NdFeB mass production, based on dry process. By ZHOFP, the oxygen content of magnet is reduced to 100–400 ppm, and magnet performance reached a higher level, the sum of (BH)max and Hcj could obtain 66–73. ZHOFP economizes rare earth resource considerably, and endues magnet with many advantages, higher energy, better temperature stability, excellent corrosion-resistance, and good consistency, which can easily meet the critical requirements of motor market. The improved coating techniques have further enhanced both the corrosion-resistance and the adhesion force of the coating. Zhenghai Oxygen-Free Process and its products have obtained patent for invention in China.