NASA SBIR 2004 Solicitation


PROPOSAL NUMBER: 04 X4.04-9708
SUBTOPIC TITLE: Servicing, Maintenance, and Repair
PROPOSAL TITLE: Nano-Phase Powder Based Exothermic Braze Repair Technology For RCC Materials

SMALL BUSINESS CONCERN (Name, E-mail, Mail Address, City/State/Zip, Phone)
Materials Resources International
811 West 5th Street Unit 2
Lansdale, PA 19446-2283

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Ronald W Smith
811 West 5th Street Unit 2
Lansdale, PA 19446-2283

MRi is proposing, with its partner, Exotherm Corp (Camden, NJ) to demonstrate the feasibility of using exothermic brazing to join RCC (or C:SiC) composites to itself and/or to metal structures as an in orbit repair technique. The proposed Phase I work would be aimed at developing powder based brazing performs that would contain elements and compounds in powder particles that have been formed to have nano-phase dispersions of reactant compounds. These powder based performs would be placed in joints that upon ignition by spark or laser would self-propagate, releasing sufficient heat to braze reinforced carbon:carbon (RCC) composite materials to RCC or to refractory metals such as tantalum or niobium. In the proposed effort MRi and Exotherm will produce nano-phase particles of two candidate precursor materials (Ti-Si-C-based and WO3-Al-Zr-SiO2), demonstrate their exothermic properties, make RCC/RCC and RCC/(Nb or)Ta joints, characterize the joints and run lap shear strength

The goal is to advance innovative, cost effective and reliable joining processes that would enable the in-flight repair of space shuttle or other reentry vehicles structures where RCC is being used. Although RCC structure repair is the specific application that is targeted, exothermic brazing technology would offer opportunity in the assembly of structures in space and on interplanetary missions, where high-energy heat sources would be difficult or impossible to use for in-flight joining, assembly and/or repair.

Exo-braze technology, if successful, has direct application in the repair of the Space Shuttle RCC thermal protection system (TPS) components. In addition the technology has much broader application both in in-space and remote planetary assembly of infrastructures. Exo-braze technology is also well suited for dissimilar materials joining and may find application in the original "terrestrial" assembly of large ceramic / ceramic-composite / metallic joints since the entire assemblies would not have to be heated. It is likely that such joining technology would be very useful in future TPS structures.

Exo-braze technology would find specific application in the joining of dissimilar materials, especially composite and ceramic composites. These materials are increasing in interest and application in aerospace, defense (such in armor or thermal protection systems for missiles) and industrial plants where the refractory and/or inertness of ceramics are required. Exothermic brazing would permit large structures of such materials to be joined without having to heat up large structures, causing CTE mismatch failures. There would also be applications in undersea joining and other remote joining where welding cannot be accomplished either due to the geometry and/or the materials, or in applications where heating a large structure that could not be welded would not be permitted.