W. Kaszuwara et al., CONSOLIDATION OF MAGNETIC POWDERS BY SHOCK COMPRESSION, Journal of materials science. Materials in electronics, 9(1), 1998, pp. 17-23
The application of shock consolidation of powder precursors using expl
osives for the processing of bulk permanent magnet materials was studi
ed. Powders of Sm-Fe-N and Nd-Fe-B produced by milling of ingot materi
al, mechanical alloying, hydrogenation-disproportionation-desorption a
nd recombination (HDDR), or by pulverizing of melt-spun ribbon were pr
essed at a shock wave speed of 1200 m s(-1) and pressures up to 4.4 GP
a. It was found that consolidation of the hard magnetic powders could
be achieved without changes of the phase structure and grain size and
that the resulting bulk magnets had high coercivities and remanences.
The final density depended on the composition of the material and on t
he initial grain size. The shock processing method was found to be par
ticularly appropriate for the consolidation of nanostructured material
s for which excessive grain growth during consolidation must be avoide
d. (C) 1998 Chapman & Hall.