Bend properties and failure mechanism of a carbon/carbon composite with a 3D needle-punched preform at room and high temperatures

Publication date: August 2016 Source:New Carbon Materials, Volume 31, Issue 4 Author(s): Dian-sen Li, Qian-qian Yao, Nan Jiang, Lei Jiang A 3D needle-punched C/C composite with a high density was fabricated and its bend properties were investigated at room and high temperatures. Macro-fracture and SEM micrographs were examined to understand the deformation and failure mechanism. Results show that the load-deflection curves below 400 °C exhibit a linear elastic and brittle fracture failure, while the curves at temperatures above 500 °C show an obvious tough and plastic failure. The bend strength and modulus decrease significantly with increasing temperature due to severe carbon oxidation. Below 500 °C, the main damage to the composite is in the form of matrix cracking, 90° fiber/matrix debonding, local twisting and fracture of the 0° fibers. Above 500 °C, the oxidation of the composite is significant and the interfacial adhesion between fibers and matrix is decreased significantly.

Source: New Carbon Materials - September 17, 2016 Category: Chemistry Source Type: research