Enhanced coercivity in SmCo5 magnet subjected to hydrogen treatment

The relations between the phase recombination conditions and phase content, microstructure, and magnetic properties of sintered SmCo5-based permanent magnets, subjected to hydrogen treatment, were studied by X-ray diffraction, scanning electron microscopy, and magnetic hysteresis loop measurements. Recombination of the disproportionation products, SmH2 +/- x, Co, and remains of SmCo5 phase, was carried out by heating the alloy in a vacuum to 850 degrees C with and without holding it for 1 h, and by heating it to 950 degrees C. It was shown that after recombination, the coercivity of the magnet, H-mu 0(c), reached the value of 4.90-4.97 T. The remnant magnetization increased from 27.7 to 43.5, and to 46.7 Am-2/kg with increasing holding time during recombination from 0 to 1 h at a temperature of 850 degrees C, and with increased recombination temperature to 950 degrees C. The hysteresis loop rectangularity changed from 77 to 74.6, and to 78.8% under the same conditions. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The relationship between phase recombination conditions and the phase content, microstructure, and magnetic properties of sintered SmCo5-based permanent magnets was investigated. It was found that by adjusting the temperature and holding time during recombination, the magnetic properties of the magnets could be improved.