TABLE OF CONTENTS A large number of industrial processes operate in very aggressive environments characterized by high temperature, increased temperature gradients, high pressure, large stresses on individual components, and the presence of oxidizing and corroding atmosphere, as well as internally created or externally ingested particulate material, which induces erosion and impact damage. A few representative examples of such processes are shown in Fig. 1.1 (Stroosnijder et al., 1994). Machines include aircraft gas turbine engines, steam turbines, industrial gas turbines, coal conversion, petroleum refining, and nuclear power generation. The generation of large amounts of heat and associated high component temperature lie at the heart of all of these processes. For example, in jet engines, fuel is mixed with highly compressed air and the mixture ignited. As a result of the heat generated, the air expands and works on the turbine to rotate it. The turbine in turn forces the compressor to rotate, which compresses the incoming air. The exiting exhaust gas creates thrust for propulsion. The gas temperature in modern gas turbine engines could well exceed 1650 C (3000 F) in the turbine section, with cooled parts reaching temperatures as high as 1200 C (2200 F). In coal gasifiers, coal reacts with steam at high temperatures to convert it into usable gas, which can be transported by pipelines and fed directly into processing plants. Process temperatures could be as high as 1650 C (3000 F) with component temperatures reaching 1090 C (2000 F). Process temperature is also high in petroleum refining as well as nuclear power generation. In...
