Unveiling the orientation sensitivity of creep life in near [001] oriented Ni-based single crystal superalloys at intermediate temperatures

Abstract

Although blades with a deviation angle of less than 15° between the blade stacking axis and the [001] orientation are qualified in the industry, the creep life of samples near [001] orientation exhibits significant anisotropy at intermediate temperatures. Those crystals having orientations within 15° from precise [001] exhibited significantly longer lives when their orientations were closer to the [001]-[101] boundary of the stereographic triangle than to the [001]-[111] boundary. Here, we first investigated the orientation rotation path of specimens near [001] orientation during creep at 750 °C/750 MPa, then revealed the dominant slip systems at different creep stages. Subsequently, we evaluated the effect of orientation deviation from precise [001] on creep properties. Finally, our research revealed the orientation sensitive mechanism of creep life in near [001] oriented Ni-based single crystal superalloys at intermediates.