Modeling of enhanced composite creep and plastic flow in temperature cycling

Abstract

It is commonly believed that new high temperature materials are critically needed to permit the production of several new aerospace and energy-related designs. Nickel-based superalloys have been well developed — such that their melting temperature places a fundamental limit on their utility at elevated temperature. Many avenues are being explored. Ceramics and intermetallics both offer much promise, but significant barriers exist in that damage tolerance must be significantly improved. One commonly suggested approach for increasing the use temperature (or possibly damage tolerance) of materials is to add a large volume fraction of a refractory material (i.e. make a composite). Many, many schemes have been suggested including both continuous and discontinuous as well as three-dimensional reinforcement schemes. Metals, ceramics and intermetallics have all been scrutinized as matrix materials, but the choice of reinforcement is usually ceramic. One obvious goal is to impart more refractory character to the material by adding a phase that is strong at high temperature.