Group leader and senior research ceramist, University of Dayton Research Institute, Dayton, OH
Associate materials scientist, University of Dayton Research Institute, Dayton, OH
Presently, continuous-fiber ceramic composites (CFCCs) are considered leading candidate materials for many high-temperature applications, such as high-pressure heat exchangers, radiant burner tubes, and engine combustors. To adequately evaluate these materials in their cylindrical configurations, a hoop tension test is needed.
A hydrostatic pressurized test was developed to obtain the hoop tensile strength from ambient to elevated temperatures (> 1500°C). The method allows only hydrostatic pressure to develop inside the cylinder to cause failure from a hoop tensile stress.
This test method evolved from testing monolithic ceramics to continuous-fiber ceramic matrix composite (CMC) tubes. The results of early hydrostatic tests are briefly reviewed. A highlight of one test identified fiber tow pull-out at 1000°C where the tube indicated localized aneurysm-type deformation. Another CFCC material system, evaluated at room temperature, exhibited fiber pull-out on the order of 5 to 7 mm. The circumferential elastic modulus was also obtained.
Paper ID: CTR10029J