Published online by Cambridge University Press: 11 July 2012
Normal spectral intensities of resistively heated preoxidized ZrB2–30 mol% SiC–6 mol% B4C specimens were measured in the 1–6 μm and ∼1100–1500 °C ranges. Using Wein’s displacement law, the temperatures of these specimens were determined, in turn permitting calculation of normal spectral emittances using Planck’s law. Spectral emittance data were affected by absorption/emission of H2O/CO2 gases; total emittances were determined from the averages of data in spectral ranges devoid of gaseous interference. Total emittances decreased from 1.0 at 1100 °C to 0.8 at 1500 °C. This trend is consistent with the behavior expected of a dielectric coating.