Results

Cu alloy anode

Creep tests were performed with Cu-50£Ni-5SAl anode and Cu-30SNi-5SiAl anode in H2-C02-H20 ( 79-19-2 ) mixture gas stream, under 5kgf/cm2 at 700 °C for 1, 000 hours. The result is shown in Figure 1. The result indicates that Cu-30S6Ni-53!Al anode has sufficient creep resistance ( less than 5% for 1,000 hours ), although Cu-30*Ni-5£Al anode has inferior to Cu-50XNi-5XAl anode in creep resistance in the condition.

Potentiodynamics polarization measurements on Cu, Ni, Cu-30SSNi alloy and Cu-503SNi alloy were carried out under an anode atmosphere ( H2-20XC02 gas bubbled in Li2C03-38mol«K2C03 molten carbonate ) at 650T! with Au reference electrode ( under an atmosphere of 33K02-67XC02 ), as Cu-Ni alloy layer is formed on the surface of Cu-Ni-Al anode which is sintered through the two-step sintering process involving both oxidation and reduction. The relation between Ni content in Cu-Ni alloy and potential is shown in Figure 2. The result indicates that the potential becomes higher as Cu content increases in Cu-Ni alloy.

Coated separator

Figure 3 shows cross section of microstructure after immersion test at 650 °C. The coating is in good adhesion and has good corrosion resistance. No defects such as crack and detach are observed in the coating. Thickness of oxide film formed on the surface of Al-Ni layer is about 5/im after 14,500 hours. This oxide film has a good protection against molten carbonate. Figure 4 shows cross section of microstructure after heat test at 650, 700, 750°C. Coating heated for 10, 000 hours is in good adhesion in specimens in both Type A and B, although voids grow near the interface of coating and substrate in Type B specimen.

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