Effects of Thermal Exposure on the Structural and Mechanical Integrity of Graphite Fibers

摘要

Three polyacrylonitrile-based (PAN-based) carbon fibers have been examined with respect to their strength degradation following elevated-temperature exposure. Fibers were heat-treated at temperatures of 1200 exp 0 C, 1500 exp 0 C, 2000 exp 0 C, and 2500 exp 0 C for 10, 20 and 30 minutes. The nitrogen concentration was found to follow an Arrhenius-type plot and an activation energy of 16.7 kJ.mol.K was found for nitrogen evolution in carbon fibers. The Thornel 300 fiber was found to degrade at high heat treatment temperatures in contrast to the Celion 6000 and IM6 fibers, which did not suffer any degradation in strength at all. (ERA citation 10:042510)