Study of the effect of high-enthalpy air flow on the efficiency of the protective action of an antioxidant coating for carbon-containing composite materials

Using the method of high-temperature chemical synthesis, material samples with a high-temperature protection system were fabricated. The study of the thermochemical effect of high-enthalpy air flows on a carbon-containing composite material with a high-temperature antioxidant coating based on hafnium compounds at surface temperatures of $1400$–$1600^{\circ}$C was carried out in a free subsonic jet of high-enthalpy air of a VGU-$4~100$-kilowatt high-frequency induction plasma torch. The experiments were carried out at a pressure of $100$ hPa in a stepwise heating mode and in a constant surface temperature mode of $1400{,}~1500{,}$ and $1600^{\circ}$C. The duration of each test cycle in the constant temperature mode was $1500$ s.