Disintegration and powder formation of
Nb75M25 (M = Al, Si, Ga,
Ge and Sn) due to hydrogenation in an arc-melting
chamberX. Li
Takahashi
(
University,
<*p(0,21.6,0,9.5,0,0,g,"U.S.
English")$f"Helvetica-Condensed">Nb75M25
(M = AI, Si, Ga, Ge and Sn) alloy ingots were prepared by conventional
arc-melting method and then were directly reacted with high purity
hydrogen of 0.1 MPa in an arc-melting chamber without exposing the ingots
to air. As the clean surface of the arc-melted ingots is preserved, the
ingots rapidly absorb a lot of hydrogen without any activation treatments
and disintegrate violently into fine particles. The disintegration of
ingots depends on M element. The collected particles are investigated by
x-ray diffraction, electron microscopy, chemical analysis and thermal
analysis. The particles are hydrides of
Nb75M25 after
hydrogenation and have a sharp-edged polygonal appearance. After
dehydriding, the fine Nb3M powders with A15
crystalline structure are obtained except for
Nb75Si25. In comparison
with the atomized Nb3M powders, the
Nb3M powders prepared by the present study have a
smaller average particle size and lower impurity contents.
Order No.:
JA809-025 © 1998 MRS
Go to September 1998 Table of Contents
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