Oxidative Degradation of Carbon-Carbon Composites
Carbon-carbon fiber composites are advanced materials with excellent strength to weight performance characteristics. However, at high temperature in the presence of aerated atmospheres, the carbonaceous fiber material will be susceptible to oxidation resulting in both mass loss and a reduction in strength. Rapid thermal flucuations common in thin components can work synergistically with the environmental degradation to produce accelerated attack. Various glasseous, multilayer ceramic coatings are often used to provide resistance to this form of environmental attack which must have both chemical resistance and controlled thermal expansion properties.
Stress Corrosion Cracking of Plastic Tubing in Potable Water
Several years ago, wide spread use of plastic tubing made was started in new house construction and for repair of old systems. The flexible tubing was used to connect the facets to the cold and hot water service. The stress corrosion crack (see arrow) developed over about eight years when exposed to hot water and the stress of bending the tubing into place.. The crack propagated through wall on the tension side of the bend and resulted in leakage. Due to the extent of this problem and the extensive water damage that it has caused to home owners, a large class action law suit resulted to recover damages.