Hybrid Oxide-Based CMCs for Combustion Turbines: How Hybrid Oxide CMC Mitigates the Design Hurdles Typically Seen for Oxide CMC

Abstract

Ceramic matrix composites (CMCs), in particular oxide-based systems, are of interest for use in combustion turbines. While uncoated oxide CMCs have significant hurdles to implementation in gas turbines, the Siemens hybrid oxide CMC system is able to overcome these challenges. These hybrid oxide CMCs provide distinct advantages over the current non-oxide based systems. The benefits of hybrid oxide-based systems for advanced gas turbines will be discussed. Material system developments will be discussed including those completed by a Siemens Power Generation led team in a recent NIST (National Institute of Standards and Technology) sponsored program to prove the concept of advanced hybrid oxide-oxide CMCs for gas turbine engines. The program fabricated a full scale outer combustor liner that was installed in a Solar Centaur 50S engine at a commercial end user site. In November 2006, this hybrid oxide CMC outer combustor liner met the target life goal of 25,000 hrs with 25,404 hrs of field test experience. The final hurdle for design of hybrid oxide CMC components is the ability to accurately analytically predict behavior. Methods and approaches to address this challenge are discussed as well.