High-Temperature Performance of Next-Generation Silicon Carbide Fibers for CMCs

ABSTRACT Single-fiber (monofilament, not twisted tow) high-temperature creep performance of refractory ceramic compositions is a fundamental material property that must be examined and understood for the successful deployment of ceramic matrix composite material systems in demanding applications. A novel creep testing approach was devised utilizing an innovative approach to fiber sample attachment and used to evaluate the creep behavior of Free Form Fibers’ LP-30SC and Nippon Carbon-based Hi-Nicalon Type S (HNS) silicon carbide fiber products. The testing apparatus, analytical basis for the creep calculations, including the sample gage length, and collected data are presented. Test conditions include a range of peak hold temperatures, from 1,300°C to 1,500°C, gas environments, and hold time patterns at the peak temperature. Clear differences in resistance to creep degradation were evident between the LP-30SC and HNS fibers, as the LP-30SC demonstrated strong resiliency to high temperature exposure while the HNS showed performance degradation consistent with oxidation attack.