- Michael Cinibulk and Randy Hay, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, Ohio
1 Overview of Structural Ceramics Research at AFRL
Two of the highest capability priorities for the Air Force, energy-efficient turbine engines and long-range precision strike capability, require high-temperature ceramic matrix composites (CMCs) to enable increased turbine engine efficiency and thermal protection of hypersonic vehicles. (CMCs currently lack the temperature capability and durability required for long life at the highest temperatures desired. This presentation highlights in-house research that is addressing the need for improved high-temperature-capable CMCs, with a focus on CMC constituents and an understanding of their processing, microstructure, and behavior in relevant service environments.
2 SiC Fiber Oxidation in Air, Steam, and Low pO2 Atmospheres
Fiber properties govern critical mechanical properties of CMCs. Oxidation affects fiber strength and therefore affects SiC-SiC CMC performance. Modeling of CMC properties requires accurate identification and modeling of oxidation mechanisms that affect CMC constituents, particularly fibers. The speaker will review oxidation kinetics, scale crystallization kinetics, and strength after oxidation of SiC fibers in air, steam, and low pO2 and will present data for steam oxidation between 500°C and 1600°C, including some results that suggest changes in oxidation mechanism above 1500°C in steam. The speaker will also identify mechanisms that degrade strength after oxidation.
About the Speakers:
Dr. Michael K. Cinibulk is principal materials research engineer and ceramic materials and processes research team leader in the Composites Branch of the Air Force Research Laboratory’s Materials and Manufacturing Directorate at Wright-Patterson Air Force Base. He is responsible for direction of in-house research focused on ceramic development, processing, and characterization of high-temperature structural ceramics.
Dr. Randall S. Hay is principal materials research engineer in the Composites Branch of the Air Force Research Laboratory’s Materials and Manufacturing Directorate at Wright-Patterson Air Force Base. He directs research on characterization and modeling of environmental effects on ceramic composite constituents.