PROPOSAL NUMBER 99-1 03.07-1833 (Chron: 991222 )
PROJECT TITLE
Brazing Innovations for Joining of Dissimilar Refractory Materials
TECHNICAL ABSTRACT (LIMIT 200 WORDS)
General Systems Company (GSC) will investigate ultra-thin Compliant Pad interlayers and diffusion solidification brazing to join dissimilar refractory materials. The goal is to provide joints capable of withstanding thermal cycling and sustained operation at temperatures > 2000?C. Thick Compliant Pad interlayers, which off-load the thermal
expansion mismatch stresses between the adherents, have been shown to produce high quality joints between graphite, alumina and TZM. This program will determine the feasibility of fabricating sufficiently thin Compliant Pads for real-world products. This program will also establish the feasibility of a diffusion solidification brazing(DSB) process where the end-use temperature may be much higher than the braze temperature. The advantages of
DSB are: a) lower braze temperature reduces residual stresses, and, b) use temperatures in excess of 2000?C should be possible. The thin Compliant Pad interlayer and DSB process development will involve IntrageneTM and NbC coatings to permit the use of non-active brazes to avoid brittle interface phases. NbC coating will also provide protection in high temperature oxidizing environments. These techniques are for ultimate use in NASA
(GSFC and MSFC) experimental furnaces and commercial products such as medical/industrial X-ray targets, the RLV engine and fiber optic draw furnaces.
POTENTIAL COMMERCIAL APPLICATIONS
The applications for dissimilar materials joining are in 1) heating elements for high temperature furnaces(commercial fiber optic draw furnaces and NASA GSFC & MSFC experimental furnaces), 2) advanced aerospace propulsion components (e.g., RLV RS 2200 linear aerospike engine nozzle ramp), and, 3) medical/industrial X-ray tube targets and electronics packaging for high power electronics. In addition applications also exist for joining of actively cooled aero structures.
NAME AND ADDRESS OF PRINCIPAL INVESTIGATOR (Name, Organization Name, Mail Address,
City/State/Zip)
Dr. Subhash Khatri
General Systems Company
1147 Plowshare Road
Blue Bell , PA 19422 - 1935
NAME AND ADDRESS OF OFFEROR (Firm Name, Mail Address, City/State/Zip)
General Systems Company
1147 Plowshare Road
Blue Bell , PA 19422 - 1935