Study On Preparation Of The New Low-density C / C Insulation Materials

With the application background of high-temperature heat insulation materials and the purpose of developing new type excellent performance heat insulation materials instead of traditional carbon felt, with carbon fiber felt as perform and thermosetting resin as precursor, impregnation, adhesion, curing, carbonization process and so on is employed to prepare a new type low density heat insulation carbon/carbon composite. The influence factors on material properties (density, mechanical properties, Thermal conductivity) including solution concentration, type of resin and felt, type and concentration of agglutinant, curing pressure are studied, the optimal condition of each factor is fixed. The structure feature of the composites have been studied using SEM. Through studying SEM photographs of samples, mechanism of layer-separated and causes of micro-defects is discussed. The conclusions can be drawn as the following:when carbon fiber felt whose density is 0.12g·cm-3 is perform, epoxy resin is precursor, solution concentration is 8%, agglutinant type is epoxy resin, agglutinant solution concentration is 65%, curing pressure is 1200Pa, density of sample is 0.15g·cm-3, thermal conductivity is 0.18W/(m·K), bending strength is 1.5 MPa, compressive strength is 0.5 MPa, various performance index of sample reach or exceed expected value, and properties have advantages more than traditional carbon felt, it is more prospective excellent performance heat insulation materials.Coating treatment is studied by CVD process. The conclusions can be drawn as follows. When deposition temperature is 1050℃, deposition time is 3 hours, N2 flow is 0.31/min, C3H6 flow is 0.151/min, density of sample is 0.22g/cm-3, bending strength is 1.1 MPa, compressive strength is 2.2 MPa, thermal conductivity is 0.25W/(m·K). Pyrolytic carbon on carbon fiber can protect internal structure, it can inhibit consumption, deterioration and pulverization of heat insulation materials, prolong its service life, avoid polluting products in furnace.