Effect of antioxidant on the efficiency of jet milling and the powder characteristics of Sm2Co17 permanent magnets

This study investigated the effect of antioxidants on the grinding efficiency, magnetic powder characteristics, microstructure, and magnetic properties of 2:17 type SmCo permanent magnet materials. The results show that adding antioxidants helps improve the dispersion among magnetic powders, leading to a 33.3 % decrease in jet milling time and a 15.8 % increase in magnet powder production yield. Additionally, adding antioxidants enhances the oxidation resistance of the magnetic powders. After being stored in a constant temperature air environment at 25 ℃ for 48 h, the O content in the powder decreased by 33 % compared to samples without antioxidants. While in the magnet body, the O content decreased from 0.21 wt.% to 0.14 wt.%, which helps increase the effective Sm content and domain wall pinning uniformity in the magnet. Excellent magnetic properties were obtained in the magnet with added antioxidants: B r = 11.6 kGs, SF = 79.6 %, H cj = 16.8 kOe, and (BH) max = 32.5 MGOe.