Improvement of the corrosion resistance on Nd-Fe-B magnet with nickel plating

Author

Minowa, T. ; Yoshikawa, Y. ; Honshima, M.

Author_Institution

Shin-Etsu Chem. Co. Ltd., Fukui, Japan

Volume

25

Issue

5

fYear

1989

fDate

9/1/1989 12:00:00 AM

Firstpage

3776

Lastpage

3778

Abstract

Three kinds of corrosion tests, a humidity test (80°C, 90% RH), an autoclave test (120°C, 2 atm saturated with water vapor), and a salt spray test (35°C, 5% NaCl), were performed on a sintered magnet treated with nickel plating. For comparison, samples with epoxy resin coating, Al ion plating, and without coating were also exposed to the corrosion test. After specified periods of corrosion testing, the permanent flux loss of the remagnetized sample was measured. Changes in appearance were also observed. It was found that the epoxy resin coating could not prevent the penetration of moisture in the humidity and autoclave tests because of its hygroscopic properties. The nickel plating and Al ion plating withstood the humidity and autoclave tests reasonably well, but they suffered slight corrosion in the salt spray test. It is concluded that the use of nickel plating can provide high corrosion resistance and low cost of production

Keywords

boron alloys; corrosion protection; corrosion testing; ferromagnetic properties of substances; iron alloys; magnetic leakage; neodymium alloys; permanent magnets; 120 degC; 35 degC; 80 degC; Al ion plating; Nd-Fe-B magnet; Ni plating; autoclave test; corrosion resistance; corrosion tests; epoxy resin coating; humidity test; permanent flux loss; remagnetized sample; salt spray test; sintered magnet; Coatings; Corrosion; Epoxy resins; Humidity; Magnetic flux; Nickel; Performance evaluation; Saturation magnetization; Spraying; Testing;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.42430

Filename

42430