Dislocation motion during high-temperature low-stress creep in Ru-free and Ru-containing single-crystal superalloys

摘要: Abstract Creep deformation of the two experimental single crystal superalloys at high-temperature low-stress (1140 °C/137 MPa) has been analyzed through transmission electron microscopy. Emphasis is placed on elucidating dependence dislocation motion microstructural evolution. The detailed analysis demonstrated that stacking fault energy γ matrix significantly decreased with addition Ruthenium (Ru). faults presenting in after heat treatment rarely reported previously. During primary creep stage, dislocations can easily cross-slip different {1 1 1} planes horizontal and leave 60° loops (0 0 1) / ′ interfacial plane. Furthermore, calculations it difficult for slipping to bow into vertical channel. In early stages steady state creep, reoriented slowly from 〈1 1 0〉 direction 〈1 0 0〉 well misfit stress relief direction. On other hand, few shearing rafted phase have observed. fact, during middle although perfect networks formed, some also addition, a 〈0 1 0〉 type superdislocations (some non-compact core) observed alloys. At last, Ru-containing alloy possesses more negative lattice misfit, denser higher stability, thus maintain minimum rate stage longer life.