Temperature Dependence of the Anisotropy and Creep in a Single-Crystal Nickel Superalloy

Abstract

The thermomechanical response of the second-generation single-crystal nickel superalloy (SC180) was obtained for wide range of temperatures (25–1000°C). Uniaxial tension and stress relaxation experiments were performed to study the influence of [100] and [110] crystallographic orientation on stress anisotropy and creep responses. Experiments were conducted using micromechanical testing systems and strains were measured using two-dimensional digital image correlation technique. Results were reported on coefficient of thermal expansion, Young’s modulus (E), yield strength, work hardening (n), and activation energies (Q). The stress relaxation experiments were used to calculate activation energy in [100] and [110] crystallographic directions and found to be 300 kJ/mol and 350 kJ/mol, respectively.