Reduction-Diffusion Preparation of Nd15Fe77B8, NdFe11Ti, NdFe10.5Mo1.5 and NdFe10.75Mo1.25 Alloys for Magnets
The calciothermic reduction-diffusion (CRD) process is a alternative preparation route for Nd15Fe77B8, NdFe11Ti, NdFe10.5Mo1.5 and NdFe10.75Mo1.25 alloys, which eliminates the need for long homogenizing heat treatment; in addition, the resulting alloy is already in powder form. We have examined the effect of various processing variables in the preparation of mother alloys. Compacts made of NdCl3, Fe, Ti, Mo and Fe-B powders and Ca granules were heated under argon for different times and temperatures. The alloys as-prepared contained mostly the hard magnetic phase. The NdFe11Ti, NdFe10.75Mo1.25 and NdFe10.5Mo1.5 alloys have been successfully nitrogenated by heating a mixture of powdered alloys with sodium azide (NaN3) at temperatures between 330 and 450 oC.
Lucio Salgado and Francisco Ambrozio Filho
E. da G. Guilherme et al., "Reduction-Diffusion Preparation of Nd15Fe77B8, NdFe11Ti, NdFe10.5Mo1.5 and NdFe10.75Mo1.25 Alloys for Magnets", Materials Science Forum, Vols. 530-531, pp. 181-186, 2006