SEDL / STP / STP439-EB / STP45882S

Infrared Testing of Bonds Between Graphite and Protective Coatings

Green, D. R.
Senior research scientist and development engineer, Pacific Northwest Laboratory, operated by Battelle Memorial Institute for the United States Atomic Energy Commission, Richland, Wash.

Day, C. K.
Senior research scientist and development engineer, Pacific Northwest Laboratory, operated by Battelle Memorial Institute for the United States Atomic Energy Commission, Richland, Wash.

Pages: 14    Published: Jan 1968

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Abstract

A nondestructive infrared method has been developed for testing bonds between coatings and graphite. Application of a special digital dual-scan technique makes the test independent of the specimen surface emittance (often called emissivity). In addition, this method does not require contact with the specimen, and can be automated for production testing. Heat was applied during tests by projecting a hot jet of helium onto the specimen surface. A commercial infrared radiometer was used to sense the resulting surface temperatures. This paper describes the theory and equipment, and some of the experimental results from tests on bonds between graphite and thin columbium carbide coatings.