Topologically Closed Packed Phase and Its Interaction with Dislocation Movement in Ni–Based Superalloy during High–Temperature Creep

In superalloys, topologically close–packed (TCP) phases, which contain refractory elements, usually significantly influence the mechanical properties. The current work investigates structure and composition of TCP phase in an Al–Mo–rich Ni–based single crystal superalloy. It is shown that after 40 h thermal exposure, a large number strip–like phases are formed, enriched Mo Re. identified as tetragonal σ with lattice parameter being 0.93 nm c 0.50 nm. During creep process, tilts obviously leads to orientation variation from <1 1 0> direction. Two groups dislocations observed deformed sample. One group contains straight dislocation lines another networks. interaction between superalloy studied reveal effect on deformation behavior. creep, hinders movement, may contribute propagation cracks final fracture.