Study of fatigue property variation at different regions on a DS turbine blade

Due to the geometry characteristics, the microstructure of different directional solidification (DS) blade regions is different during the solidification process, which suggests that the mechanical properties may also show variation among these regions. Three types of DS specimens (platform-like, shroud-like and notched) are designed to investigate the differences through high temperature low cycle fatigue tests. Tests results show that the fatigue performances of the shroud-like specimen and the platform-like specimen are respectively 7.68% and 5.93% those of the notched specimen. Therefore, the difference of fatigue property among different regions on a DS turbine blade should be considered in blade structure design and fatigue life prediction. The research results may also help to improve the fabrication processes of directional turbine blade solidification.