Sub-solvus cellular recrystallization and P phase formation in a single-crystal superalloy containing Re

Abstract

Sub-solvus recrystallization behavior of a second-generation single-crystal superalloy has been studied by transmission electron microcopy and scanning transmission electron microcopy. Surface local stress facilitated cellular recrystallization accompanied with formation of twin structure and TCP phase of P during annealing at sub-solvus temperature of 1,100 °C. The precipitation of P phase is considered to be attributed to the coarsening of γ′ phase in the recrystallized aggregates which lower the activation energy for atomic migration.