Engineered Composite Materials for Hypersonic Wind Tunnel Applications

Survivability of the throat and nozzle materials employed in hypersonic wind tunnel systems is a key issue for the design and development of such testing facilities. The state-of-the-art nozzle systems materials (intermetallic alloys or refractory metals) are prone to degradation due to oxidation at high temperatures. Ceramic Matrix Composites (CMCs) are potential candidates for such high temperature applications due to their high temperature strength and oxidation resistance. Alumina is a valuable candidate for such applications because of its excellent high temperature chemical stability. However, alumina lacks in thermal shock resistance and toughness. The innovation that SMAHT Ceramics has envisioned and is proposing is aimed at overcoming the intrinsic limitations of Alumina by simultaneous addition of zirconia polycrystals (TZP) and SiC (chopped) fibers as minor phase toughening agents. The SiC (chopped fibers) will be dispersed in the composite in random 3-D orientations using a proprietary technique developed by SMAHT. In this manner, SMAHT offers to engineer an isotropic, reliable, and durable high temperature composite suitable for the (transient) ultra-high temperature applications in hypersonic windtunnel. For the successful commercialization of this advanced composite technology, low-cost and net-shape / production-friendly processes will be developed and utilized at SMAHT.