Form 9.B Project Summary

Chron:

970752

Proposal Number:

20.09-4239

Project Title:

Braze Joining of SiC Composite RLV

Propulsion Components

Technical Abstract (Limit 200 words)

Joints between very dissimilar materials - e.g.

metal-to-ceramic, are required in a number of

aerospace, commercial and industrial systems.

Brazing is often the preferred joining technique

owing to compatibility, performance, cost and

scalability advantages. However, the traditional

brazed dissimilar material joints are likely to have a

relatively low strength because of the high residual

stress in the joint region. Also, brazing compounds

frequently use active metal additions to promote

wetting of the adherend surfaces. Though active

metal additions do increase the joint strength in the

short term, it has been shown that under elevated

temperature operation, the joint strength falls with

time. Foster-Miller's unique braze joint concept

approach overcomes both brazing problems.

During Phase I, Foster-Miller will demonstrate an

innovative, practical and low cost brazing

technology for elevated temperature RLV

propulsion components. The Phase I program will

involve selection of materials to be joined with input

from NASA COTR, design and build-up of the

braze product form, fabrication of joint coupons, and

testing consisting of physical characterization and

mechanical, thermal cycling. The follow-on Phase II

program will involve refinement of design,

materials, procedures and process parameters.

Phase II joint coupons will be subjected to a

comprehensive test plan. A demonstration article of

specific interest to NASA will be built during Phase

II. The Phase II program will involve the following

commercialization partners - braze product

manufacturer, brazing service provider, NASA

systems integrator.




Potential Commercial Applications (Limit 200 words)

Brazing is commonly used for joining of metallic and

ceramic materials. The proposed technology has

commercial applications involving attachment of

dissimilar materials. These include: compact

furnace components, hypersonic plane structures,

rocket and gas turbine engines, X-ray and

semiconductor sputtering targets, and industrial

applications such as attachment of tubular products

in pipelines, heat exchangers, chemical, oil drilling

and mining slurry transport tubes, etc. Additionally,

a reliable, practical and low cost joining technique

for dissimilar materials will provide a new

dimension for reducing component cost for

designers, e.g. use different materials in strategic

regions of a component.

Name and Address of Principal Investigator (Name,

Organization Name, Mail Address, City/State/Zip)

Uday Kashalikar

Foster-Miller, Inc.

350 Second Avenue

Waltham , MA 02154-1196

Name and Address of Offeror (Firm Name, Mail Address,

City/State/Zip)

Adi R. Guzdar

Foster-Miller, Inc.

350 Second Avenue

Waltham , MA 02154-1196