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The corrosion behaviour of NiAl in Molten Carbonate at 650°C
Author(s) -
Vossen J. P. T.,
Janssen A. H. H.,
de Wit J. H. W.
Publication year - 1996
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.19960471208
Subject(s) - nial , corrosion , metallurgy , materials science , carbonate , intermetallic , alloy
In Molten Carbonate Fuel Cells (MCFC) the separator plates in a stack are exposed to severe conditions. The normal operating temperature of a MCFC is 650°C, while the electrolyte consists of an eutectic mixture of 62/38 Li 2 CO 3 /K 2 CO 3 . On one side the separator plate material is in contact with a reducing atmosphere and on the other side it is an oxidising atmosphere. Due to the application of a wet seal the material is also in contact with the molten carbonate. A wide range of materials is therefore being investigated to enable a justified materials selection either as base material or as coating. NiAl is one of the investigated materials, which has promising properties, due to the possible formation of a protective oxide LiAlO 2 layer. A comparison will be made with data available for pure Ni, with special emphasis on the protective character of the oxide layer based on quasi‐stationary polarisation curves, exposure tests at open circuit potential and quenching experiments, incorporating earlier published results obtained on Ni with impedance measurements. All experiments were performed in molten carbonate, while the gas composition over the melt was 64% H 2 , 16% CO 2 , and 20% H 2 O.