TY - JOUR
T1 - Corrosion assessment of Nd-Fe-B alloy with Co addition through impedance measurements
AU - Sunada, Satoshi
AU - Majima, Kazuhiko
AU - Akasofu, Yasuhiro
AU - Kaneko, Yuji
PY - 2006/2/9
Y1 - 2006/2/9
N2 - Effect of Co addition on improving the corrosion resistance of Nd 11.8Fe82.3-xCoxB5.9 specimens with different x (x = 0, 2.5, 5.0, 7.5, 10.0) have been investigated through the electrochemical method including the impedance measurement. With increasing amount of Co content the natural electrode potential shifted to nobler side. The Nyquist plot showing a semi circle in which frequency increases in counter clockwise direction was obtained. From the result it was clarified that the diameter of the semi circle corresponding to the charge transfer resistance, Rct, became larger with increasing Co content, which indicates the improvement of the corrosion resistance for the Nd11.8Fe 82.3-xCoxB5.9 specimens by Co addition because the Rct is inversely proportional to the corrosion rate. Judging from these results it is suggested that the impedance measurement is one of the effective methods to obtain the information of corrosion behavior for the Nd11.8Fe82.3-xCoxB5.9 specimens.
AB - Effect of Co addition on improving the corrosion resistance of Nd 11.8Fe82.3-xCoxB5.9 specimens with different x (x = 0, 2.5, 5.0, 7.5, 10.0) have been investigated through the electrochemical method including the impedance measurement. With increasing amount of Co content the natural electrode potential shifted to nobler side. The Nyquist plot showing a semi circle in which frequency increases in counter clockwise direction was obtained. From the result it was clarified that the diameter of the semi circle corresponding to the charge transfer resistance, Rct, became larger with increasing Co content, which indicates the improvement of the corrosion resistance for the Nd11.8Fe 82.3-xCoxB5.9 specimens by Co addition because the Rct is inversely proportional to the corrosion rate. Judging from these results it is suggested that the impedance measurement is one of the effective methods to obtain the information of corrosion behavior for the Nd11.8Fe82.3-xCoxB5.9 specimens.
KW - Charge transfer resistance
KW - Corrosion resistance
KW - Immersion test
KW - Nd-Fe-B magnet
KW - Nyquist plot
UR - http://www.scopus.com/inward/record.url?scp=31144468497&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2005.04.039
DO - 10.1016/j.jallcom.2005.04.039
M3 - 会議記事
AN - SCOPUS:31144468497
SN - 0925-8388
VL - 408-412
SP - 1373
EP - 1376
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
T2 - Proceedings of the Rare Earths'04 in Nara, Japan
Y2 - 7 November 2004 through 12 November 2004
ER -