Mass spectrometer studies of hydrogen desorption from hydrided NdFeB

Author

Williams, A.J. ; McGuiness, P.J. ; Harris, I.R.

Author_Institution

Sch. of Metall. & Mater., Birmingham Univ., UK

Volume

26

Issue

5

fYear

1990

fDate

9/1/1990 12:00:00 AM

Firstpage

1945

Lastpage

1947

Abstract

The desorption of hydrogen from NdFeB powder and unmilled material produced using hydrogen decrepitation as a premilling technique was investigated using a mass spectrometer to monitor the hydrogen partial pressure in the system as the sample was heated under vacuum from room temperature to ~1000°C. A comparison was made between powder exposed to the atmosphere for 10 min and powder exposed for one month. There was found to be a reduction in the amount of hydrogen desorbed from the Nd-rich grain boundary phases, and there was a change in the shape of the desorption peak from the Nd₂Fe₁₄B phase as the level of oxidation increased. Studies were also carried out on alloy hydrided at room temperature in situ, and these showed a variability in the amount of hydrogen desorbed from the Nd-rich grain boundary phases

Keywords

boron alloys; desorption; ferromagnetic properties of substances; heat treatment; iron alloys; mass spectroscopic chemical analysis; neodymium alloys; permanent magnets; powders; 10 min; 1000 C; H decrepitation; H desorption; NdFeB powder; NdFeBH_x; grain boundary phases; mass spectrometer; oxidation; permanent magnets; premilling technique; Atmosphere; Grain boundaries; Hydrogen; Mass spectroscopy; Monitoring; Powders; Shape memory alloys; Temperature; Vacuum systems; Vacuum technology;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.104579

Filename

104579