Amorphous ultra-fine powders in (Fe or Co)-B and Fe-M-B (M=Cr, Mn, Co, or Ni) systems were produced by reduction of metal ions in an aqueous solution by use of KHB4. The powders have a spherical shape with diameters ranging from 5 to 20 nm. The boron concentration is in the range of 24.1 to 44.1 at. pct and the composition of metal elements can be controlled by changing the concentration of metal ions. Crystallization temperatures and heats of crystallization for the Fe-Ni-B powders agree with those obtained for the amorphous alloys of the same composition produced by melt spinning. It is concluded that there is no significant difference in the amorphous structure obtained in chemically synthesized powders and the melt-spun ribbons, in spite of an essential difference in the formation mechanism of these amorphous alloys.
|ジャーナル||Metallurgical transactions. A, Physical metallurgy and materials science|
|出版ステータス||Published - 1988 1 1|
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