Tensile behavior and deformation mechanism of secondary generation single crystal superalloy DD6 at 1070 C

Abstract

Keywords: DD6; Single crystal superalloy; Tensile behavior; fractographs; Microstructures; Abstract. The tensile behavior of secondary general single crystal superalloy DD6 with low Re was investigated at 1070˚ C. In this study, orientation of the specimens was selected along the (001) direction and the evolution of microstructure and dislocation configurations were analyzed by SEM and TEM in detail. The results reveal that the stress—strain curves exhibit a curved feature, and fracture mechanism shows dimple model. After the tensile deformation at 1070˚ C, the γ' phase morphology of DD6 alloy was maintained cubical. Due to the dissolution of γ' phase and tensile stress loaded at 1070˚C, the matrix channel is broadened. Consequently, the main deformation mechanism is that dislocations slip in matrix channels, and overcome the γ' phases through by-passing process.