| Abstract: | Nickel‐base superalloys used for critical rotating disc components have evolved into advanced, high performance, application‐specific materials. The designs of modern turbine machinery applications have dictated a shift in material performance requirements from an emphasis solely on burst and creep strength to the addition of minimized fatigue crack growth rates and component residual stresses. Increased component performance has often resulted in material and process changes that are accompanied by subsequent manufacturing difficulties. For example, increased alloy content has pushed the primary processing route from ingot metallurgy toward powder metallurgy methods. The processing routes required in the manufacture of these materials are equally as complex as the alloys themselves and have a strong influence on the resultant properties of turbine engine discs. Challenges still lie ahead for material and process engineers working on these materials. Both turbine engine design changes and market pressures will mandate novel materials and processes that allow for cost effective solutions for the harsh environment applications these nickel‐based superalloys have evolved to fill. |
