The carbon/carbon(C/C) composite was prepared by repeatedly overlapping the layers of 2D carbon cloths, and the 2D C_f/SiC composites were subsequently prepared in vacuum by a liquid silicon infiltration process. The ...The carbon/carbon(C/C) composite was prepared by repeatedly overlapping the layers of 2D carbon cloths, and the 2D C_f/SiC composites were subsequently prepared in vacuum by a liquid silicon infiltration process. The flexural strength of samples obtained under different preparation conditions was investigated. The results show that the composite has a better performance when the mass of silicon powder is 1.5 times greater than that of C/C composite, the temperature of silicon infiltration is 1550 ℃ and the holding time of silicon infiltration is 3 h. The density and flexural strength of the composite are 2.15 g/cm^3 and 128 MPa, respectively, and the thickness of the SiC layer is 12 μm.展开更多
The Cf/SiC composites were prepared by precursor conversion-hot pressing sintering with AIN and Y2Os as additives. The effects of sintering temperature and additives on the microstructures and properties of the compos...The Cf/SiC composites were prepared by precursor conversion-hot pressing sintering with AIN and Y2Os as additives. The effects of sintering temperature and additives on the microstructures and properties of the composites were investigated. The composite sintered at as low as 1 75O℃ already showed higher density and better mechanical properties, which was mainly attributed to the liquid-phase-sintering and the formation of the AIN-SiC solid solution. With increasing the sintering temperature to 1 800 ℃, the flexural strength and fracture toughness of the composite were substantially improved up to 691. 6 MPa and 2O. 7 MPa’ m1/2 respectively in spite of the slightly elevated density, and the composite exhibited "tough" failure. Despite the improved density, the composite sintered at 1 85O℃ displayed brittle failure, which mainly attributed to the strongly bonded fiber/matrix interface and the degradation of the properties of the fibers.展开更多
文摘The carbon/carbon(C/C) composite was prepared by repeatedly overlapping the layers of 2D carbon cloths, and the 2D C_f/SiC composites were subsequently prepared in vacuum by a liquid silicon infiltration process. The flexural strength of samples obtained under different preparation conditions was investigated. The results show that the composite has a better performance when the mass of silicon powder is 1.5 times greater than that of C/C composite, the temperature of silicon infiltration is 1550 ℃ and the holding time of silicon infiltration is 3 h. The density and flexural strength of the composite are 2.15 g/cm^3 and 128 MPa, respectively, and the thickness of the SiC layer is 12 μm.
文摘The Cf/SiC composites were prepared by precursor conversion-hot pressing sintering with AIN and Y2Os as additives. The effects of sintering temperature and additives on the microstructures and properties of the composites were investigated. The composite sintered at as low as 1 75O℃ already showed higher density and better mechanical properties, which was mainly attributed to the liquid-phase-sintering and the formation of the AIN-SiC solid solution. With increasing the sintering temperature to 1 800 ℃, the flexural strength and fracture toughness of the composite were substantially improved up to 691. 6 MPa and 2O. 7 MPa’ m1/2 respectively in spite of the slightly elevated density, and the composite exhibited "tough" failure. Despite the improved density, the composite sintered at 1 85O℃ displayed brittle failure, which mainly attributed to the strongly bonded fiber/matrix interface and the degradation of the properties of the fibers.
