High temperature tensile properties of 2D cross-ply carbon-carbon composites

Abstract

High temperature tensile properties of 2D carbon-carbon composite made from high strength T700 carbon fibers were evaluated at different temperatures. Carbon-carbon composites were heat treated at different temperatures i.e., 750, 1000, 1500, 2000, 2500 °C and their tensile properties were measured at room temperature and at different high temperatures. It is observed that, maximum value of tensile strength at room temperature is of composite heat treated at 1500 °C thereafter strength decreases with increasing processing temperature up to 2500 °C. The decreases in strength are related to degradation of fiber properties in composites and in-situ damage. On the other hand, tensile strength is higherat high temperature compared to room temperature. It increases progressively with increasing the test temperature up to 2000 °C. Thereafter, strength decreases and ultimate valueof tensile strength is less than that of the room temperature value of 2500 °C heat treated composites. Increase in strength up to 1500 °C is due to the improvement in fiber-matrix interactions, matrix properties due to relaxation of thermally induced stresses duringhigh temperature test. Above 1500 °C enhancement in tensile strength is due to the enhancement in strength of carbon fibers and due to the creep deformation. Decrease in strengthat measurement temperature 2500 °C is due to the additional in-situ degradation of fiber properties during high temperature test. © 2011 VBRI press.