Unique Reinforcement Architecture for Impact Resistant Carbon-Carbon Leading Edge

The 2003 Columbia tragedy, in which impact damage to the Shuttle's reinforced carbon-carbon (RCC) leading edge thermal protection system caused later disintegration of the spacecraft upon reentry, has highlighted the need for more impact resistant carbon-carbon composite materials. It is believed that the conventional 2D carbon fiber ply architecture used by NASA may not be capable of providing adequate impact resistance. KaZaK proposes to use its expertise in manufacturing carbon-carbon composite precursors to develop and test RCC composites with a unique reinforcement architecture based on novel woven carbon fiber preforms augmented by carbon nanotube toughening. Composites manufactured from carbon fiber preforms similar to the ones proposed here have recently been shown to exhibit surprising improvements in mechanical properties over conventional composites, including 30% increase in tensile strength, greater than an order of magnitude improvement in fatigue life as well as increase in stiffness and reduction in delamination damage. KaZaK will test the assumption that impact resistance will be greatly improved over RCCs based on 2D or 2.5D conventional ply technology by the combination of more microscopically uniform reinforcement architecture and whiskerized carbon fibers (via CNT addition) in C-C composites manufactured from this novel precursor technology.