SBIR-STTR Award

There is an urgent need to develop low-cost, damage tolerant, reusable and lightweight hot structure technology applicable to atmospheric entry vehicles, exposed to extreme temperatures between 1000° C to 2200° C. Advanced carbon-carbons (C-C) and carbon fiber reinforced ceramic matrix composites (CMC) are the most promising and possibly the most affordable light-weight material candidates for these identified applications. Since mid-1980s, many advancements, including but not limited to (1) internal inhibition using glass forming particulates (2) oxidation resistant ceramic matrices and (3) advanced coating systems, have demonstrated and have significantly improved the performances of carbon fiber reinforced composites under oxidative environment at high temperature. Unfortunately, none of these SOTA CMCs even with the advanced and expensive coating system are inherently oxidative resistant with proven reliability and therefore are not capable to meet the challenges required by multiple usage applications. In Phase I, Allcomp proposes to demonstrate the feasibility of inherently oxidation resistant C-C and C-SiC composites capable to operate between 1000° C to 2200° C by fine-tuning our innovative nano-scaled glass forming and internal inhibition technologies using scalable and production-ready processes. Once proven, coupled with advanced adherent and crack free external coating systems currently being developed at Allcomp, this new class of CMCs will enable hot structures meeting the challenges of multiple uses applications up to 2000 °C (4000 °F) with significantly improved reliability at reduced risks. Potential NASA Applications Expendable and Re-usable Hypersonic Vehicles and the Scramjet - Hot structures for Aeroshell and Scramjet for both man-rated and unmanned vehicles Launch System – Exit Cone and Hot Components in Engine Hot Gas Flow Path Advanced Exploration System - Hot structures to replace parasitic thermal protection systems, includes future planetary missions including Mars and Venus, primary benefit significant weight reduction Potential Non-NASA Applications Potential applications of hot structures for DoD and Commercial Space applications including: primary load-carrying aeroshell structure, control surfaces/ leading edges & fins, hot gas flow duct of the scramjet, and various components in engine hot gas flow path of the propulsion system such as hot gas valves, throat, and nozzle extensions.

NASA future applications require non- incremental advances in high temperature materials. Specifically, advanced future propulsion systems require significant improvement in the upper temperature operating limit of composite materials. Carbon-carbon (C-C) composites exhibit unique properties on increasing strength with temperature but suffer from oxidation at temperatures above 550 C. Over the years significant efforts in the oxidation protection of C-C composites included internal inhibition, external coatings and sealants. The reliability of such oxidation protection system is greatly limited by the intrinsic risk of coating spallation. On the other hand the internal inhibition by itself is incapable of providing sufficient substrate protection at high temperatures without the external coatings. Phase I results provided initial paradigm shift into the feasibility of internal oxidation protection system for 3500 F to 4200 F applications. This Phase II builds on very encouraging and insightful Phase I results and provides for a comprehensive, unique molecular level inhibition of the fiber, intrabundle matrix and interbundle matrix. System chemistry will be optimized to offer NASA a plethora of opportunities in such demanding applications as extension nozzles and combustors offering max temp operation up to 4,200 F with the material system chemistry and molecular inhibition design enabling the composite based parts to experience very large temperature gradients and providing effective oxidation protection of the substrate. In short, the uniqueness of this molecular inhibition system, based on Allcomp’s provisional patent, eliminates the need for external coatings and sealants. By the elimination of the external coatings the huge coating spallation reliability problem will be solved offering a paradigm shift applicable not only to NASA propulsion applications but the plethora of other NASA applications, military, and commercial applications. Potential NASA Applications (Limit 1500 characters, approximately 150 words) An inherently oxidation resistant molecular-inhibited C-C composites without the need of external coating protection capable for operating at temperature up to 4200 F can be easily scaled up at low cost for large extension nozzles, high temperature integrated combustor / throat/ exit cone, and advanced heat shields for NASA’s launch vehicles and re-entry vehicles. Examples are NASA Space Launch System and Robotic Lunar Vehicles - Lunar Orbital Platform Gateway to Lunar Surface. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words) Advanced oxidation resistant C-C can be used in in the propulsion path of advanced missiles systems and for the hot structure of the hypersonic vehicles. In the commercial space market, light weigh, low cost, and scaleable oxidation resistant C-C can also be in the propulsion path of their launch vehicles.