Because carbon-carbon (C/C) composites have superior high-temperature thermophysical and mechanical properties than other materials, they are currently the first choice for solid rocket motor nozzle throat linings. During the working process of the engine, the C/C composite throat lining will be damaged due to the erosion and ablation of the heat flow of high temperature, high pressure, high speed and containing erosive particles under the harsh thermal environment, which is manifested as the expansion of the throat diameter. The surface is rough and uneven, the profile is irregular, etc., which affects the working pressure of the engine and reduces the efficiency of the nozzle.

Example: When 10%-25% of the HfC material produced by our company is added to the carbon matrix of the nozzle throat lining of a certain type of weapon system, the ablation resistance of the HfC-C/C composite material can be greatly improved. The contribution of HfC to the ablation resistance of the throat lining of HfC-C/C composites mainly includes two aspects: (1) At the ablation temperature of 3500 °C, HfC preferentially reacts with oxygen to form HfO2 during the high-temperature ablation process, which effectively prevents the oxidation with carbon matrix and carbon fibers in composite materials under oxygen atmosphere; ②Because HfC has high strength and hardness, it effectively improves the overall anti-mechanical abrasion and erosion performance of the material, so that the mechanical erosion of gas on the inner profile of the throat lining effectively suppressed. Obviously, the ablation resistance of HfC-C/C composites increases with the increase of HfC content. The HfC-C/C composite throat lining has good ablation resistance under the test conditions of the solid rocket motor.