Low Cost Enhanced Conductivity C-C for Reusable Hot Structure and Leading Edge Applications

Owing to their low density and exceptional ability to maintain strength atnbsp;extremely high temperatures, advanced carbon-carbons (C-C) compositenbsp;isnbsp;the preferred structuralnbsp;materialnbsp;for atmospheric entrynbsp;applicationsnbsp;where the vehicles at hypersonic speed are exposed to extreme temperatures (2000deg;F to 4000deg;F)nbsp;andnbsp;oxidizing atmospheres.nbsp; In addition to structural integrity at temperatures up to 4000deg;F, the material used fornbsp;thenbsp;leading edgenbsp;also needs good thermal conductivity in order to spread the highly localizednbsp;heat flux to a larger radiating surface and avoid thermal runaway.nbsp;Operations usingnbsp;the advanced C-C composites are generally expensive due to high material fabrication costs and oxidation wear-out /nbsp;single use.nbsp; Reusable load-carrying ceramic matrix composites (CMC)nbsp;have being developed for hot structure applications with some success;nbsp;however, only C-C composites have shown abilitynbsp;to meet the extremenbsp;temperature amp; heat conduction requirements fornbsp;leading edge applications.nbsp;Building on knowledge gained with aircraft break products, anbsp;novel C-C composite architecture with readily tunable thermal mechanical propertiesnbsp;that employsnbsp;lower-cost carbon fibersnbsp;and has a shorter manufacturing lead time is proposed.nbsp; Additionally, nano-inhibition is proposed to mitigate the oxidation concerns, hencenbsp;improvednbsp;damage tolerance and structurenbsp;re-usability are expected.nbsp;In Phase I, Allcomp proposes to focus on the leading edge application requirements and demonstrate (1)nbsp;manufacturability of anbsp;lower cost, shorter lead time C-C architecture,nbsp;(2)nbsp;feasibility to modulate thermal mechanical properties withnbsp;preform stack designnbsp;and densification process enhancements, and (3) inclusion ofnbsp;selected anti-oxidation technology to improve damage tolerance.nbsp; Once proven, this architecture will offer other hot structure applications, such as aero-shell andnbsp;propulsion components, lower cost options with improved reliability.