Electrochemical-impedance study of the corrosion of Ni and FeAl intermetallic alloy in molten (0.62Li, 0.38K){sub 2}CO{sub 3} at 650 C
The corrosion of Ni and FeAl in molten (0.62Li, 0.38K){sub 2}CO{sub 3} mixtures at 650 C in air has been examined by the electrochemical-impedance spectroscopy (EIS) technique. The impedance spectra for Ni showed the typical characteristics of diffusion-controlled reaction, i.e., a semicircle at the high-frequency port and a line at the low-frequency port. The corrosion of FeAl also presented the of a diffusion-controlled reaction during initial immersion. However, the impedance spectra were composed of two capacitance loops after some immersion time. The change of the impedance spectra with immersion time may be ascribed to the formation of continuous external LiFeO{sub 2} and an inner Al{sub 2}O{sub 3} layer. Equivalent circuits representing the features of the corrosion of Ni and FeAl were proposed to fit the impedance spectra and electrochemical parameters in the equivalent circuits were also calculated. Based on the measurement of diffusion impedance, the diffusion of O{sub 2}{sup -} was proposed to be the predominant feature of oxygen reduction.
- Research Organization:
- Inst. of Corrosion and Protection of Metals, Shenyang (CN)
- OSTI ID:
- 20020591
- Journal Information:
- Oxidation of Metals, Vol. 53, Issue 3-4; Other Information: PBD: Apr 2000; ISSN 0030-770X
- Country of Publication:
- United States
- Language:
- English
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