In designing materials for structural applications, materials scientists must make trade-offs among the strength, toughness, and operating conditions to achieve optimal properties for particular applications. One particularly successful method for controlling these trade-offs is to combine materials with complementary properties in a composite. The ability to operate at high temperature is especially important, because small changes in engine efficiency translate into lighter engines and support structures.
Less weight means that the aircraft has to carry less fuel.
Therefore small improvements in materials translate into large initial and operating cost savings for aerospace systems. We have been performing a series of calculations on the CRAY C90 at SDSC to predict the adhesion between different high-temperature materials. These calculations are aimed at understanding the fracture behavior of new generations of strong and tough composites for gas-turbine engine applications. However, between two dissimilar materials, the nature of the bonding is inherently different than within either of the materials and plays a central role in a wide range of technologically important fields, such as fracture, friction, wear, and corrosion protection. The bond strengths ultimately determine how difficult it is to fracture a composite even though much more of the energy of fracture is associated with creating and moving defects.