Title :
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
fDate :
9/1/1997 12:00:00 AM
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;
Journal_Title :
Magnetics, IEEE Transactions on
