Long-term ablation-resistant nitrogen-containing carbide ultra-high temperature ceramic with ultra-high melting point and application thereof

A long-term ablation-resistant nitrogen-containing carbide ceramic, wherein a density of the long-term ablation-resistant nitrogen-containing carbide ceramic is greater than or equal to 99.8%, and a C/N content distribution is uniform, and wherein the long-term ablation-resistant nitrogen-containing carbide ceramic is prepared by the following steps:

• step 1:
• preparing a HfC powder and a HfN powder according to a mass ratio of HfC:HfN=(1-7):1, uniformly mixing the HfC powder and the HfN powder with a carbon powder and a carbon nitride powder to obtain a mixed powder, wherein an amount of the carbon powder is greater than 0 wt. % and does not exceed 8.0 wt. % of a mass of the mixed powder, and an amount of the carbon nitride powder is greater than 0 wt. % and does not exceed 5.0 wt. % of the mass of the mixed powder;
• and
• step 2:
• performing a spark plasma sintering on the mixed powder obtained in step 1 to produce the long-term ablation-resistant nitrogen-containing carbide ceramic, wherein conditions of the spark plasma sintering re:
• a temperature in a sintering furnace is 1500-2400° C., a holding time is 5-60 minutes, a heating rate is 5-150° C./min, a cooling rate is 5-150° C./min, a pressure is 20-60 Mpa, and a vacuum degree is less than 5 Pa.