METHOD OF PRODUCING ULTRAHIGH-TEMPERATURE CERAMIC MATERIAL BASED ON HAFNIUM CARBONITRIDE Russian patent published in 2020 - IPC B22F3/23 C04B35/56 C22C29/02 C04B35/645 

FIELD: space technologies; material science.

SUBSTANCE: method of producing ultrahigh-temperature ceramic material based on hafnium carbonitride involves preliminary mechanical activation of a mixture of initial components consisting of 96.7 wt% Hf and 3.3 wt% C in high-energy ball planetary mill, subsequent self-propagating high-temperature synthesis (SHS) of the prepared mixture Hf and C and consolidation of synthesized powders. Preliminary mechanical treatment is carried out for 5–10 minutes at ratio of weight of balls to mass of mixture 20:1–40:1 and rotation speed of planetary disc 694–900 rpm, then SHS is carried out in reactor in nitrogen atmosphere 0.1–0.8 MPa. Initiation of self-sustaining exothermic reaction is carried out by incandescent tungsten spiral. Consolidation of synthesized hafnium carbonitride powder is performed by spark plasma sintering method, at that, argon atmosphere is created and sintered sample is passed pulse current from 1,000–5,000 A at load 30–70 MPa, consolidation temperature and holding time are 1,900–2,200 °C and 2–10 minutes, respectively.

EFFECT: considerable reduction of power inputs and synthesis time of the material.

1 cl, 6 dwg, 1 ex