题　目：Design of ceramic matrix composites for gas turbine applications

报告人： Dr. Hagen Klemm

　　　　　　Fraunhofer Institute of Ceramic Technologies and Systems, Dresden, Germany

时　间：9月23日（周五）上午9:30-11:00

地　点：李薰楼468房间

Abstract:

In spite of the ambitious efforts to increase the portion of alternative and renewable resources the energy production based on fossil fuels will still represent the main part of energy in the next years. Caused by the increasing energy price and the stronger requirements in environmental protection focus of future generations of gas turbines will be emphasized on an increased efficiency with a simultaneous reduction of the emissions. From technical point of view, these goals can be obtained only by higher hot gas temperatures.

Ceramic matrix composites (CMC) offer high potential for application in gas turbines to fulfill these goals. A superior property level of CMC (mechanical, chemical and thermo-physical) has been achieved, however, the long-term stability up to application relevant times of more than 10 000 h in the severe hot gas environment have to be assured.

First, the principle design of the system fiber – fiber coating – matrix must be qualified according the application requirements. Special emphasis was placed on fiber coating systems with high oxidation and corrosion resistance in order to assure a damage tolerant behavior of the CMC in long-term applications at elevated temperatures.

A second main challenge was found to be the corrosion resistance of the materials in hot gas environment. Environmental barrier coatings were developed in order to prevent the hot-gas corrosion processes at the surface of the materials. However, property degradation of the CMC was observed as the consequence of diffusion and reaction of hot gas components (O₂, H₂O) in the bulk CMC component.

In the present study, some idea about the design of the whole system CMC - EBC will be provided.