Effect of Matrix Carbon on Compressive Properties of Needled Felt Carbon/Carbon Composites
【摘要】：Carbon/carbon composites with different type of matrix carbon were prepared using needle punched felt and different fabrication schemes. Thermal gradient chemical vapor infiltration of the felt resulted in a final high density of 1.75 g/cm3 with pyrolytic deposition of carbon matrix. A part of the sample was treated at a high temperature of 2500 °C for a lower density(1.70 g/cm3) sample with micro and macro cracks in matrix and interface. A part of the lower density sample was further densified using pitch impreg-nation and carbonization at a pressure of 0.3 MPa. After 04 cycles,a final higher density of 1.85 g/cm3 was achieved with pitch carbon in the interfacial,open pores and crack areas of the composite. The higher density sample was also exposed in oxy-acetylene environment at 2800°C for 90 seconds. Ablated sample was then tested for compressive strength along with other different density samples. Their compressive behavior was determined and discussed in the light of type of matrix and matrix microstructure. There was a progressive increase in compressive properties with the rise in density and improved interfacial properties. After ablation testing,the higher density sample showed even better properties when compared with the same density sam-ple before ablation testing.