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

摘要

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.