Development of environmental barrier coatings for non-oxide ceramics

ABSTRACT

This review article outlines the authors’ previous works on environmental barrier coatings (EBC) for non-oxide ceramics and discusses what has been revealed since then. It also provides an overview of the research on eutectic coatings as EBC's that has been carried out in recent years. The authors have developed EBC for Lu₂O₃-doped silicon nitride ceramics. Since preliminary material screening tests revealed that Lu₂Si₂O₇ phase has superior resistance against water vapour corrosion, the development was carried out mainly on EBC's based on this phase. This review addresses recession behaviours in static state and dynamic steam jet water vapour environments for some oxides, as well as under steam jet test for silicon nitride ceramics with EBC's, in addition to fabrication of EBC's with oxides eutectic structure. One example of the authors’ works is described here, since it can fabricate a crack-free Al₂O₃–HfO₂ eutectic coating.

KEYWORDS:

• EBC
• Lu2Si2O7
• Al₂O₃-HfO₂ eutectic

Disclosure statement

No potential conflict of interest was reported by the author(s).