Powder metallurgical processing of Tb sub 0. 27 Dy sub 0. 73 Fe sub 2 minus x (0 lt x le 0. 5) by hydrogen decrepitation

Journal Article · Mon Apr 15 04:00:00 EDT 1991 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.347872· OSTI ID:5624510

Jones, D G.R.; Fairclough, J P; Abell, J S; Harris, I R ^[1]

---

1. School of Metallurgy and Materials, University of Birmingham, Birmingham, United Kingdom (GB)

This paper reports on the characterization of giant magnetostrictive alloys, of the general formula Tb{sub 0.27}Dy{sub 0.73}Fe{sub 2{minus}{ital x}} (0{lt}{ital x}{le}0.5), at various stages during their powder processing by hydrogen decrepitation, in order to try to optimize the process. Mass spectrometer degassing studies on hydrogenated material have shown that disproportionated material exhibits two desorption peaks and is not degassed completely with respect to hydrogen until above 600 {degree}C. The RFe{sub 2} (R=Tb{sub 0.27}Dy{sub 0.73}) hydride powder appears to degas at a lower temperature; however, it is thought that a high-temperature desorption peak is not present due to oxidation. Metallographic studies have shown that there is much less rare-earth-rich grain-boundary phases in sintered compacts of initial composition RFe{sub 1.5} than in cast RFe{sub 1.5} and also reveal the microstructure of hydrogenated and disproportionated RFe{sub 1.5}. Wavelength dispersive x-ray analysis seems to indicate preferential loss of Dy during sintering.

• OSTI ID: 5624510
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 69:8; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
ALLOY SYSTEMS
ALLOYS
CHEMICAL REACTIONS
CRYSTAL STRUCTURE
DYSPROSIUM ALLOYS
GRAIN BOUNDARIES
HYDROGENATION
IRON ALLOYS
MAGNETIC PROPERTIES
MAGNETOSTRICTION
METALLURGY
MICROSTRUCTURE
PHYSICAL PROPERTIES
POWDER METALLURGY
RARE EARTH ALLOYS
TERBIUM ALLOYS
TERNARY ALLOY SYSTEMS