Heat transfer and behavior of ultra high temperature ceramic materials under exposure to supersonic carbon dioxide plasma with additional laser irradiation

Abstract

The behavior of the ultra high temperature ceramic material HfB2-SiC-C(graphene) under exposure to a supersonic carbon dioxide plasma, with and without the addition of laser irradiation, has been studied. The material was heated to 1750 °C in an inductively coupled plasma jet without laser irradiation. A temperature jump to 2190 °C was observed when additional ytterbium laser irradiation was applied to the surface. The spectral emissivity of the heated surface at wavelengths of 0.65 and 0.9 μm was studied. It was found that the spectral emissivity decreases as the material oxidizes. The heat flux to the surface of the heated material was measured and compared to the heat flux to a cold copper surface under the same conditions. Analysis of the surface of HfB2-SiC-C(graphene) material after exposure was performed. Differences in microstructure were detected between specimens exposed to carbon dioxide plasma with and without additional laser irradiation.