Preparation of Amorphous Ultra-Fine Powders in (Fe, Co, Ni)-B Systems by a Chemical Reduction Method and Properties of Their Sintered Products

Junji Saida, Akihisa Inoue, Tsuyoshi Masumoto

Research output: Contribution to journalArticle

Abstract

Amorphous ultra-fine powders in (Fe, Co, Ni)-B systems were prepared by a chemical reduction method using KBH4. The powders have a spherical morphology with diameters ranging from 20 to 50 nm. The boron concentration is in the range of 25 to 35 at.% and chemical composition of the metal elements can be controlled by changing the concentration of metal ions. Crystallization temperature (Tx) and heat of crystallization for an ultra-fine Fe50Ni22B28 powder agree with those obtained for the amorphous alloy with the same composition prepared by melt spinning. The reaction process consists mainly of the process of preparing Me2B and Me (Me=Fe, Co, Ni). Furthermore, the amorphous powders were found to be consolidated to a fully dense amorphous bulk by uniaxial pressing at temperatures below Tx. Their densities are almost equal to those of the corresponding arc-melted crystalline powders. Hardness values of the hot-pressed compacts are considerably lower than those of the melt-spun amorphous ribbons with the same composition.

Original languageEnglish
Pages (from-to)944-947
Number of pages4
Journaljournal of the japan society of powder and powder metallurgy
Volume38
Issue number7
DOIs
Publication statusPublished - 1991 Jan 1
Externally publishedYes

ASJC Scopus subject areas

  • Mechanical Engineering
  • Industrial and Manufacturing Engineering
  • Metals and Alloys
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Preparation of Amorphous Ultra-Fine Powders in (Fe, Co, Ni)-B Systems by a Chemical Reduction Method and Properties of Their Sintered Products'. Together they form a unique fingerprint.

  • Cite this