Abstract
In order to find a new energy-saving-powder manufacturing process, the pulverization due to hydrogenation of Nb-Zr-Fe alloys with 35 different compositions has been studied. The hydrogenation was performed under the hydrogen atmosphere of 0.1 MPa and room temperature in an arc melting chamber without exposure to air after arcmelting.
Nb-Zr-Fe alloys absorb a large amount of hydrogen from 0.1 to 1.8 wt%H and pulverize into powders. This pulverization is closely related to the composition of alloys.
The composition which is easy to pulverize is concentrated to the ranges of 15 at%Fe in Nb-Zr-Fe alloys and 15-30 at%Fe with fixed to Nb/Zr??1/1 in Nb-Zr-Fe alloys. For an example, hydrogen absorbed powder of 45Nb-40Zr-15Fe alloy has wide size distribution from 5 to 200 micron with flake figure and with many fine cracks.
The hydrogen in powder of 45Nb-40Zr-15Fe alloy is stably stable until 473 K and dehydrogenation temperature is from 473 K to 773 K.
It is estimated that hydrogenation is induced by proper amount of iron element in Nb-Zr-Fe alloys and a hydrogen rich phase and a hydrogen poor phase are formed in an alloy ingot. Forming of two phases by absorbing hydrogen causes to pulverization of Nb-Zr-Fe alloys.
