Modeling of mechanical properties of alloy CMSX-4

High efficiency in gas turbines requires increased gas temperatures. Gas temperatures above 1100 °C can only be handled using air-cooled structures to keep the metal temperatures below 1000 °C. Single-crystalline superalloys meet the requirements for creep strength and thermo-mechanical fatigue resistance. Single-crystalline superalloys are used for gas turbine blades. Modeling of deformation is a key issue in order to develop life prediction tools. In this study modeling of creep deformation and creep rupture as well as fatigue contribute to a description of the mechanical behavior of CMSX-4 at three different temperatures. Creep deformation was described by modified Garofalo equation and a Larson-Miller approach. Cyclic elastic-plastic deformation as well as fatigue life were described by a new engineering approach. Here the elastic-plastic deformation work was considered in order to determine a temperature-dependent master curve for fatigue behavior.