SGER- Development of Iota-Alumina Coatings

Trustees Of Boston University, Boston

Investigators

Abstract

0122539 Basu An SGER award supports a study of the feasibility of depositing compositionally graded coatings in the mullite-iota alumina system. The intent is to develop coatings which will provide high temperature oxidation and corrosion resistance to SiC and Si3N4 ceramics without spalling during thermal cycles. The intent is to CVD deposit a coating which is mullite (3Al2O3.2SiO2) at the interface with the ceramic substrate and to gradually change the composition to pure alumina of the iota-alumina phase, which has the same crystal structure as mullite. The coatings will be evaluated for crystal structure, thermal expansion properties, and high temperature oxidation resistance. ***