IRREVERSIBLE LOSSES OF MAGNETIZATION IN FE-ND-B TYPE MAGNETS

Irreversible losses of magnetisation for magnets, based on Fe-Nd-B all oys processed by melt spinning, HDDR, and sintering and on Fe-Nd-C-B i ngot material, have been evaluated. Magnets having the same intrinsic properties and coercivity but different compositions and processed by different routes exhibit the same losses. Thus, optimization of the al loy composition, phase constitution and microstructure of the magnets, leading to high coercivity, appears to be crucial for minimisation of the irreversible losses of magnetisation.