The emissivity of carburized rhenium

Abstract

Reflection techniques were used to measure the spectral emissivity at a wavelength of 0.65 μm of 30‐μm‐thick Re foils containing 5 at.% C. When heated to a temperature above that for saturated solubility (1900 K) so that all carbon was in solution, the emissivity was 0.420.04, the same as that of pure Re. Heating at a lower temperature caused growth of a graphitic film on the surface and the emissivity increased to 0.700.10. When subjected to intermediate temperatures, the ribbon exhibited emissivity patches, and the average emissivity under these conditions was estimated to be 0.620.04.