Experimental measurements and quantified approach of spectral emissivity of cupronickel alloy C7701 during oxidation.

• Spectral emissivity data of cupronickel alloy C7701 is first reported. • Emissivity of cupronickel alloy in different oxidation degrees are measured. • The quantified approach of emissivity during oxidation is established. In this paper, the emissivity of the cupronickel alloy C7701 during oxidation is measured at temperatures of 673, 773, 873 and 973 K over the spectral range from 2 to 22 μm. The measurement details including the experimental setup, the measuring method and the sample preparation are introduced. The effects of wavelength, temperature and heating time on emissivity are discussed. The cupronickel alloy samples in different oxidation at long wavelength degrees are prepared, and the corresponding emissivity data is measured. The surface micromorphology and composition of cupronickel alloy samples are analyzed by scanning electron microscope and X-ray diffraction to further study the influence of surface oxidation. Finally, a fitting model is established to quantitatively reveal the characteristics of emissivity with the heating time, and the emissivity relative errors of the fitting model are analyzed to be less than 4%. [ABSTRACT FROM AUTHOR]