The ablation of carbon carbon composite material throat is mainly from complex gas environment,and the main reason includes: carbon sublimation, surface chemical reaction, mechanical erosion,and the fiber properties, prefabricated structure,material density, porosity, matrix carbon, degree of graphite, impurity,and there are some factors that affect the interaction.
Carbon carbon composite material has many good properties,such as high specific strength, high specific modulus, high temperature resistance, corrosion resistance, thermal shock resistance,and chemical stability. Now the carbon carbon composite material is double functional composite material with structure material and thermal protection materials,and it’s already widely used in aerospace industry and other industrial system.
Carbon carbon composite material now is the preferred material for nozzle throat. During the working state,the carbon carbon nozzle throat is under the very bad thermal environment,under the high temperature and high pressure,the caliber of the throat will be enlarge,the surface will be out-of-flatness,and it will have a big influence to the work pressure of the engine and it will also reduce the working efficiency of the nozzle,it will even make the engine failure.
The mechanical properties and ablation properties most depends on the different type and quality of the carbon fiber. The carbon fiber used for carbon carbon composite material has many different kinds,such as :PAN base,pitch base etc.and each different kinds of the carbon fiber can be divided into a number of series.
The difference from matrix carbon, physical and mechanical properties, the arrangement of carbon fiber, production technology,so the mechanical erosion will also be different,some can be erosion in partical state,and some can be erosion in big piece. So we need to confirm the raw material,the structure of matrix carbon and different production technology to improve the properties of carbon carbon composite material.
