Anisotropic Tensile Properties in Ni-Based Single-Crystal Superalloy DD6 near [001] Orientation at 760°C

Abstract

This work is concerned the tensile properties of the secondary Ni-based single-crystal superalloy DD6 near [001] orientation at 760°C. In this study, anisotropic tensile properties of DD6 alloy within 10° of the [001] orientation were exhibited at 760°C. The yield strength and ultimate tensile strength of DD6 alloy oriented close to [001] direction was the highest. As the deviation off the [001] orientation increased, both 0.2% yield strength and ultimate tensile strength was decreased. The specimens oriented close to [001]-[111] boundary exhibit higher yield strength and ultimate tensile strength than the specimens oriented close to [001]-[011] boundary. Numerous of dislocations can be found in the γ matrix channels during the tensile deformation. A number of dislocation pairs and few of stacking faults are found in the γ' precipitates after the tensile at 760°C. The morphology of γ' phases in DD6 alloy maintained cubical during the tensile deformation at 760°C. With Schmid's Law, the mechanism of anisotropic tensile properties in DD6 alloy near [001] orientation is analyzed.