Influence of Oxidation on Fracture Toughness of Carbon-Carbon Composites for High-Temperature Applications

Carbon-Carbon Composites (C-CC), used as composites for their remarkable qualities in the space industry as well as in many other industry sectors. C-CC has proven to be the most efficient material in extreme temperature situations. One of the best high-temperature materials with good thermal quality, such as high-temperature stability, outstanding thermal conductivity and low-temperature expansion coefficients. In aircraft, railways, trucks and even race vehicles, C-CC brake disks are in high demand. In comparison to the favorable thermal and mechanical qualities of C-CC, their great sensitivity to oxidation in an oxidizing environment at temperatures even around 400°C is a major restriction with these composites. In particular, a study of the C-CC oxidation mechanism helps to create protective measures for these composites. The present experimental study explores the influence of oxidation in static air on the fracture toughness of C-CC. At a temperature of around 400°C to 700°C in an increase of 100°C, an oxidation evaluation of the material was carried out in static air. Results show a decrease in fracture toughness to increase in the temperature. We can observe that C-CC fracture toughness is severely affected by oxidation. The variation began at 400°C from 6% and was anticipated at 700°C up to 45%

Defence Applications of Polymer Nanocomposites

The potential opportunities promised by nanotechnology for enabling advances in defence technologies are staggering. Although these opportunities are likely to be realised over a few decades, many advantages are currently being explored, particularly for defence applications. This review provides an insight into the capabilities offered by nanocomposites which include smart materials, harder/lighter platforms, new fuel sources and storage as well as novel medical applications. It discusses polymer-based nanocomposite materials, nanoscale fillers and provides examples of the actual and potential uses of nanocomposite materials in defence with practical examples.Defence Science Journal, 2010, 60(5), pp.551-563, DOI:http://dx.doi.org/10.14429/dsj.60.57