0000000000744641
AUTHOR
W. Nowy-wiechuła
ANNEALING EFFECT ON COERCIVITY AND MICROHARDNESS IN SINTERED (Nd, Tb)15(Fe, Co, Al)78B7 MAGNETS
The variation of the coercivity and microhardness with annealing (475–1150°C/3.6 ks) of sintered (Nd, Tb) 15 (Fe, Co, Al) 78 B 7 permanent magnet have been investigated. The data indicate that the coercivity reaches the mininum and the maximum at 600°C and 775°C, respectively. Optical and scanning electron microscopy and magnetic domain structure observations give no hints to any change in microstructure. Fitting of the Mössbauer spectra of permanent magnets for different coercivity ( i H c ) values revealed that magnetic hyperfine fields (B Hf ) on all Fe sites are reduced with the increase in i H c value and the higher value of the i H c corresponds to the higher value of the Mössbauer l…
Corrosion behaviour of sintered Nd(Fe,Al)B magnets
Abstract The effect of 1–6 at% Al additions to a sintered NdFeB magnet on its corrosion behaviour was tested. The additions do not influence the magnet's corrosion behaviour in the active state and cause beneficial effects in the passive state. The Al additions inhibit atmospheric corrosion of the magnets.