Research Progress in Environmental Barrier Coatings of SiC Ceramic Matrix Composites

Abstract

SiC matrix ceramic composites (CMC-SiC) are considered as the potential primary structural materials in advanced gas turbines because of their low density, good oxidation resistance and high-temperature strength. However, CMC-SiC suffers from serious degradation in the gas environments. With the protection of environmental barrier coatings (EBCs), CMC-SiC composites can be possibly applied as hot components with long lifetime in the aero-engine. The materials selection requirements, development history, preparation process, assessment technologies and characterization methods of EBCs materials system were introduced in this paper. The open problems of EBCs materials system such as high volatile rate, low operating temperature during service and low crystalline fraction, low density of the coatings during the preparation process were summarized and analyzed. The research goal and development direction in the EBCs system optimization, fabrication process development and evaluation and assessment platform were put forward.

Keywords

• aero-engine
• CMC-SiC composite
• environmental barrier coating