Microstructure and magnetic properties of sintered Nd-Fe-B magnets with high hydrogen content

Journal Article · Fri Apr 01 00:00:00 EDT 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3563082· OSTI ID:21538251

Guo, S; Zhou, Q Y; Chen, R J; Lee, D; Yan, A R ^[1]

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1. Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, CAS, Ningbo 315201 (China)

The effects of hydrogen contents after the process of hydrogen decrepitation on the magnetic properties and corrosion resistance of sintered Nd-Fe-B permanent magnets have been studied. The intrinsic coercivity of the magnets increases and the remanence decreases with increasing hydrogen content. High residue hydrogen content in the starting ingot leads to the reaction of hydrogenation, disproportionation, desorption and recombination in the sinter process resulting in magnets with low remanence. The results of highly accelerated temperature/humidity stress test indicate that excessive hydrogen contents are harmful to the corrosion resistance of the magnets. The influences of residue hydrogen contents on the corrosion resistance of magnets dominate only when the residue hydrogen content exceeds 1300 parts per million.

• OSTI ID: 21538251
• Journal Information: Journal of Applied Physics, Vol. 109, Issue 7; Conference: 55. annual conference on magnetism and magnetic materials, Atlanta, GA (United States), 14-18 Nov 2010; Other Information: DOI: 10.1063/1.3563082; (c) 2011 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BORON ALLOYS
COERCIVE FORCE
CORROSION RESISTANCE
CRYSTAL STRUCTURE
DESORPTION
FERROMAGNETIC MATERIALS
HUMIDITY
HYDROGEN ADDITIONS
HYDROGENATION
IRON ALLOYS
MAGNETIC PROPERTIES
MICROSTRUCTURE
NEODYMIUM ALLOYS
OXIDATION
PERMANENT MAGNETS
RECOMBINATION
RESIDUES
SINTERING
STRESSES
ALLOYS
CHEMICAL REACTIONS
EQUIPMENT
FABRICATION
MAGNETIC MATERIALS
MAGNETS
MATERIALS
MOISTURE
PHYSICAL PROPERTIES
RARE EARTH ALLOYS
SORPTION
TRANSITION ELEMENT ALLOYS