Compressive mica seals for SOFC applications

Muscovite and phlogopite micas have been assessed as SOFC seals at 800°C. Paper gaskets, composed of pressed mica platelets in an organic binder, proved ineffective seal materials predominantly because of their uneven surface. However, cleaved natural mica sheets (with no binder) indicated far superior sealing characteristics with leak rates lower than 0.1 sccm cm−1 at 800°C, and approximately 0.7 MPa (100 psi) compressive stress.