The corrosion protection of RE-iron-boron magnets by a phosphate treatment

Author

Costa, I. ; Sayeg, I.J. ; Faria, R.N.

Author_Institution

Inst. de Pesquisas Energeticas e Nucl., Sao Paulo, Brazil

Volume

33

Issue

5

fYear

1997

fDate

9/1/1997 12:00:00 AM

Firstpage

3907

Lastpage

3909

Abstract

The effect of a phosphate treatment as a corrosion inhibitor for a RE-iron-boron magnet has been investigated. The corrosion characteristics of the magnet in a phosphate solution, which consisted of 0.15 M NaH₂PO₄, were analyzed by electrochemical impedance and electrochemical noise measurements. The immersion of the magnet in the phosphate solution resulted in the formation of a passive layer on its surface causing a prolonged corrosion protection, after removal from the solution. The protective layer was found to consist of phosphate/pyrophosphate and oxide by XPS analysis

Keywords

X-ray photoelectron spectra; boron alloys; corrosion protection; electrochemistry; ferromagnetic materials; iron alloys; noise; passivation; permanent magnets; rare earth alloys; surface treatment; NaH₂PO₄; RE-iron-boron magnets; XPS analysis; corrosion inhibitor; corrosion protection; electrochemical impedance; electrochemical noise measurements; magnet; oxide; passive layer; phosphate treatment; phosphate/pyrophosphate; protective layer; Coatings; Corrosion inhibitors; Frequency; Low-frequency noise; Magnets; Noise level; Noise measurement; Protection; Surface impedance; Surface resistance;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.619611

Filename

619611