High Fracture Toughness in Ultra-High Temperature Ceramics

Air Force and NASA contractors are in need of ultra-high temperature materials with improved toughness properties for hypersonics and rocket propulsion applications.  This SBIR will make available a new technology that can significantly increase the fracture toughness of existing and emerging ultra-high temperature ceramics and composites.  Ormond, LLC has developed data that indicates cavitation peening can be used as a novel low cost means of significantly improving fracture toughness in ceramics.  This process is available nowhere in industry and it is capable of developing high intensity, deep compressive stresses similar to laser shock peening (LSP), but at a small fraction of the cost, without the technical flaws, and in ceramics.   The proposed Phase I SBIR will demonstrate the feasibility of improving fracture toughness in ultra-high temperature materials, including ceramics and composites.  Process development will include parametric testing and high temperature tests to demonstrate process performance.  Phase II will end with a working prototype system that will be available as a low cost method of significantly enhancing the fracture toughness of the full range of ultra-high temperature ceramics and composites, as well as high temperature metals such as Inconel, rhenium and Gr-Copper.    BENEFITS: This dual use technology will see widespread defense and commercial applications.  While this SBIR specifically addresses improving fracture toughness in ultra-high temperature materials, the developed technology will extend to many ceramics, metal matrix and ceramic matrix composites.  The need for improved fracture toughness in ceramics is felt across industry. Cavitation peening is a low cost process.  When compared to laser shock peening, cavitation peening has capital cost that is an order of magnitude less.  The operating cost is only a small fraction of LSP as well, and the process speed is significantly higher.  LSP has not been demonstrated affective on ceramic materials.   The Phase II program will provide the funding to fully develop the process and any new prototype tooling that may be required.  Demonstration coupons and data will be provided to Air Force primes along with manufacturing cost data.  The technology will be ready for production implementation on completion of the Phase II effort. Army ballistic testing has demonstrated that Ormond significantly improved the shock absorbing capacity of silicon carbide ceramics using cavitation peening.  Several metals have been peened at Ormond with elevated fatigue strength as a result.  These indicators demonstrate that Ormond will be successful in addressing the ultra-high temperature topic area.