SURFACE DEGRADATION OF CERAMIC MATERIAL BASED ON THE ZrB-HfB-SiC SYSTEM UNDER THE INFLUENCE OF A SUBSONIC FLOW OF DISSOCIATED NITROGEN CONTAINING 5 mol. % CO

Ultra-high-temperature ceramics based on zirconium and hafnium diborides are of great scientific and technical interest, as they can be very promising, including as components of descent vehicles for space exploration. To study the behavior of these ceramics under the influence of high-speed flows of dissociated gases of complex composition and to determine the effect of modifying the ZrB-HfB-SiC system with carbon nanotubes, the process of surface degradation under the influence of a subsonic flow of dissociated nitrogen containing 5 mol. % CO was examined. Despite the relatively low CO content in the nitrogen plasma, the surface oxidation process dominated the conversion of the initial ZrB/HfB into solid solutions based on monocarbonitrides of these metals. In this case, it was noted that a protective layer of silicate glass does not form on the surface, unlike similar materials under the influence of subsonic flows of dissociated air at temperatures