Anisotropy of the critical resolved shear stress of a γ′(47 vol.%)-hardened nickel-base superalloy and its constituent γ-and γ′-single-phases

Single crystals of the commercial nickel-base superalloy NIMONIC 105 with four different orientations have been compression tested in the temperature range 600–1150 K. NIMONIC 105 is strengthened by fine, coherent, shearable, homogeneously distributed precipitates of the L12-long-range ordered γ′-phase (47 vol.%). The same investigations were undertaken for single crystals of the two constituent phases: L12-ordered, intermetallic single-phase γ′ and disordered single-phase f.c.c. γ-matrix. Their compositions were those of the two equilibrium phases of NIMONIC 105. The CRSS of NIMONIC 105 and of the γʹ-phase were anisotropic in the whole temperature range. The CRSS of the γ-matrix was isotropie. The interpretation of the anisotropy of NIMONIC 105 follows that of single-phase L12-ordered γ′.