3-D Graphite-Copper Composite Heat Exchanger

Foster-Miller proposes a 3-D graphite-copper (Gr/Cu) composite to meet the strength and transverse thermal conductivity criteria set forth in the solicitation. In conjunction with the NASP office of Rocketdyne, Phase I will develop this unique composite to replace the current NARloy Z heat exchanger for the NASP ramjet inlet. The 3-D Gr/Cu composite is comprised of a 2-D graphite fiber textile in which ultra-high thermal conductivity Z-fiber mini-pultrusions are inserted at key rib and facesheet locations. The preform would then be infiltrated with molten copper using the near net shape Pressurized Shell Mold Casting (PSMC) process. High infiltration pressure combined with small amounts of active alloying elements ensure total fiber wetting and no matrix porosity. Through the use of dissolvable tooling, it may be possible to cast pin heat exchangers directly into the coolant channels. In Phase I, Foster-Miller will develop textile methods and a pressure casting process to produce 3-D Gr/Cu coupons for mechanical and thermal property testing. Rocketdyne will incorporate these properties into thermal and structural models and produce preliminary Gr/Cu heat exchanger designs. An option task would further investigate producibility issues for fabricating a composite heat exchanger component.