TOTAL HEMISPHERICAL EMITTANCE AND NORMAL SPECTRAL EMITTANCE (LAMBDA = 0.65 MICRON) OF OXIDATION PROTECTIVE COATINGS.
Abstract
Measurements of the variation of total hemispherical emittance and normal spectral emittance (Lambda = 0.65 micron) with increasing temperatures have been made on some pack-cementation disilicide type oxidation resistant coatings for the refractory metals, molybdenum, tungsten, niobium and tantalum. The normal spectral emittance (Lambda = 0.65 micron) of the coatings on disc samples, was determined with a micro-optical pyrometer, which was sighted into a black body hole, drilled in the sample and then onto the adjacent area. The total hemispherical emittance of the coatings on ribbon specimens was found by use of a calibrated total radiation pyrometer, which sampled the energy radiated from a uniform temperature region established about the center portion of the electrically heated ribbon specimen. The diffuseness of the surface of the various coatings was found by taking angular distributions of the radiation emitted from the center portion of the sample ribbons at various temperatures with the total radiation pyrometer. The confidence limits placed on these data are = 15 percent. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1963
- Accession Number
- AD0423179
Entities
People
- N. J. Alvares
Organizations
- Naval Radiological Defense Laboratory