材料期刊网

A modified layered ternary compound (Ti0.98Nb0.02)(3)(Si0.95Al0.05)C-2 was evaluated as a new interconnect material for intermediate temperature solid oxide fuel cells (IT-SOFC). The results indicated that the compound has low density (4.50 g/cm(3)), closer matched thermal expansion coefficient with Y2O3 stabled ZrO2 (9.0 x 10(-6)/K), low room temperature electrical resistivity (24 mu Omega cm), and good mechanical properties and machinability. During the isothermal oxidation at 600 degrees C-800 degrees C, a monolithic layer with the mixture of rutile TiO2 and amorphous SiO2 formed on (Ti0.98Nb0.02)(3)(Si0.95Al0.05)C-2. Its oxidation kinetics roughly follows a parabolic law, the rate constant is 0.45, 1.26, 1.57 x 10(-7) mg(2)/cm(4) s at 600 degrees C, 700 degrees C, 800 degrees C, respectively. After the oxidation at 700 degrees C and 800 degrees C in air for 100 h, its area special resistance is 5 and 12 m Omega cm(2) at the corresponding oxidation temperature, respectively. In oxidizing environment, (Ti0.98Nb0.02)(3)(Si(0.95)A(10.05))C-2 is very stable, and has not Cr or other element volatilization. All above determined properties of (Ti0.98Nb0.02)3 (Si0.95Al0.05)C-2 are favorable for its application as interconnect in IT-SOFC. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.