A Study on Carbon Fiber Reinforced Carbon Composites for Frictional Applications

ABSTRACT This paper presents the synthesizing of carbon-carbon (CC) composites by preformed yarn (PY) method and its mechanical properties, by varying the percentage of carbon fiber. The PY used is carbon fiber bundle surrounded by coke and pitch which is enclosed in nylon-6. Three types of samples with fiber weight fractions of 30%, 40% and 50% respectively, are fabricated and tested. In each case, the PY is chopped and filled into a die of required shape and hot pressed at500°C to 600°C to get the preformed composite. To obtain the carbon or graphitic structure, the specimen is heat treated at 1200 0 C, 1800°C and 2000C followed by soaking for two hours. Further, two cycles pitch impregnation is done by hot isostatic pressing, to eliminate the excess voids. The characteristics such as hardness, compressive strength, density and wear resistance are studied. It is observed that, as the carbon fiber percentage increases the properties also improved. Key words: Carbon-carbon composite; Preformed Yarn; Carbon fiber; Sintering; Hardness