Improved corrosion and temperature behaviour of modified Nd-Fe-B magnets

Author

Tenaud, P. ; Vial, F. ; Sagawa, M.

Author_Institution

Aimants UGIMAG, St. Pierre d´´Allevard, France

Volume

26

Issue

5

fYear

1990

fDate

9/1/1990 12:00:00 AM

Firstpage

1930

Lastpage

1932

Abstract

The characteristics of the high energy product NdFeB magnets obtained by the powder metallurgy route have been improved by appropriate vanadium additions. Specific combinations of V and Co lead to an intrinsic coercive force of about 1350 kA/m (17 kOe) in Dy-free magnets, without any large decrease of remanence. If 1.5-at.% Dy is added, load line down to -B/μH=0.5 can be achieved at 180°C without irreversible losses. Corrosion resistance is improved by blocking the selective oxidation of the Nd-rich phase. As a consequence, organic-coated magnets are able to withstand 15 days at 115°C-1.75 bars in a H₂O saturated atmosphere without any degradation. It is concluded that this set of new properties will enlarge the application fields of Nd-F-B permanent magnets

Keywords

boron alloys; coercive force; iron alloys; neodymium alloys; remanence; 180 degC; Dy-free magnets; H₂O saturated atmosphere; Nd-F-B permanent magnets; Nd-rich phase; NdFeB:Co; NdFeB:V; coercive force; corrosion resistance; organic-coated magnets; powder metallurgy; remanence; selective oxidation; temperature behaviour; Atmosphere; Bars; Coercive force; Corrosion; Magnets; Oxidation; Powders; Remanence; Temperature; Thermal degradation;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.104574

Filename

104574