Porous ceramic fiber glass matrix composites for solid oxide fuel cell seals

摘要

Porous ceramic fiber glass matrix composites with porosities of 19-24% were prepared with mixtures of a glass and short alumino-silicate ceramic fibers for the sealing of solid oxide fuel cells. The sealing performance was evaluated by measuring leak rates at the seal operation temperature of 650 degrees C and by investigating adherence at seal-metal interfaces after the seal test. Composite seals prepared with 55 vol% glass in the mixture showed a leak rate of similar to 105 sccm/cm and did not adhere to the metal tube. Leak rate could be reduced to similar to 0.003 sccm/cm when using composite seals prepared with 65 vol% glass. The maximum size of the pores present at the seal interface was estimated from the standard leak rate by assuming a single leak hole. (C) 2006 Elsevier B.V. All rights reserved.