Stress-rupture behavior of a Re-containing Ni-base single crystal superalloy at high temperatures

A Re-containing Ni-base single crystal superalloy was used to investigate the elementary processes associated with stress-rupture behavior at different temperatures where the gamma' rafting occurs. At 900 degrees C, the rupture behavior is mainly determined by the multiplication of dislocations within the widening gamma channels, which is closely linked with the propagation of microcracks along the inherent gamma/gamma' interfaces. The rapid formation of lamella gamma/gamma' raft structure, along with the developed-well interfacial dislocation networks, and its elastic instability are primarily responsible for the rupture behavior at 1100 degrees C. There is a clear curvature tendency in the Larson-Miller plot of stress-rupture lifetime in relation to stress at high temperatures. It indicates that the influence extent of gamma' rafting on stress-rupture behavior is sensitive to the acting conditions of temperature and stress. (c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.