Ceramic composite materials have the capability to sustain high stress in the presence of high temperatures and aggressive atmospheres. Such materials are being considered for application as cumbustors, burner tubes, heat exchangers, headers, hot-gas filters, and even rotors of stationary gas turbine engines. In the present program, Nicalon preforms of tubular geometry were fabricated with different fiber architectures (filament winding, 3D braiding, or cloth winding) to tailor the mechanical properties for specific applications. However, these applications require that candidate materials be carefully characterized. Mechanical characterization must establish the properties and performance that are essential for structural design of the turbine components. For this purpose, a full complement of properties is needed, i.e., the stiffness and strengths of the composite materials at a range of temperatures, and the fatigue and creep behavior of the materials under the stress states anticipated by the user. This mechanical characterization requires specialized equipment and methodologies, which are now under development by the authors. This paper will present a description of the methodologies required for ceramic composite characterization, and will describe initial results for ceramic composite tubes, a representative geometry for gas turbine components. Future needs and opportunities will also be discussed.
Synthesis and characterization of ceramic composite materials based on silicon-carbide and cordierite