Deformation Mechanisms of Tandem Hot Rolled GH4169 Superalloy during Creep

Abstract

AbstractBy means of direct aged treatment, creep property measurement and high resolution TEM microstructure observation, the deformation mechanisms of Tandem Hot Rolled GH4169 superalloy during creep are investigated. Results show that, after direct aging treatment, fine γ″ particles with different sizes and shapes dispersedly precipitate in the alloy, which is one of important factors for the alloy possessing good creep resistance. And the deformation mechanisms of the alloy are that the deformed twinnings with different orientations are activated on {111} plane by pole mechanism, thereinto, the twinning dislocation may continuously slip around a pole axis dislocation on the twinning planes when the applied stress exceeds the critical value, and the twinnings may multiply by the dislocation reactions and mutual indemnification. As creep goes on, the denser dislocations with single or double orientations slip in the different twinnings, which play an important role of coordinating the grain deformation to enhance the creep resistance of the alloy.