Abstract
The effect of crystallographic orientation on the tensile/compressive creep strengths of single crystals of a nickel-based superalloy was examined at 750°C under the constant nominal resolved shear stress for {111}<112> slip system. Initial orientations of tensile/compressive specimens were selected within 10 deg of the [001] pole. The {111}<112> type slip systems were found to be operative during the tensile/compressive creep deformations. The orientation dependence of creep strength and deformation mechanisms were different between tension and compression. The dominant deformation mode in tension was occurred by {111}<112> viscous slip; however, the creep mechanism in compression was twin formation associated with viscous {111}<112> slip.
