The tensile behavior of carbon fibers at high temperatures up to 2400 degrees C

The tensile behavior of four different brands of carbon fibers (a rayon-based, a PAN-based, and 2 pitch-based fibers) has been investigated at various temperatures up to 2400 degreesC. The tests were carried out using an original fiber testing apparatus. Various mechanical properties including strength and Young's modulus, as well as Weibull statistical parameters were extracted from test data. Typical tensile behaviors were evidenced such as an essentially linear elastic behavior at room temperature and intermediate temperatures up to 1400-1800 degreesC, then a nonlinear elastic delayed response at higher temperatures and ultimately an inelastic response with permanent deformations at very high temperatures. Such unusual nonlinear responses for homogeneous materials were related to structure and texture features at the nanometer scale, that were described through an X-ray diffraction technique. (C) 2004 Elsevier Ltd. All rights reserved.