Al-doped Nd-Fe-B permanent magnets: wetting and microstructural investigations

The coercivity of Nd-Fe-B sintered magnets has been improved by Al additions. To study the microstructural effect of Al addition, two types of investigation were formed: (1) the change in the wetting behavior of the liquid phase, at the sintering temperature, was studied by measurements of the wetting angle; and (2) the microstructural changes resulting from Al additions were studied by transverse electron microscopy assisted by energy dispersive X-ray analysis. A systematic change was detected that depended on the kind of Al addition, i.e., metallic or as Al/sub 2/O/sub 3/.< >