ANISOTROPY OF THE CRITICAL RESOLVED SHEAR-STRESS OF A GAMMA'(47 VOL.PERCENT)-HARDENED NICKEL-BASE SUPERALLOY AND ITS CONSTITUENT GAMMA-SINGLE-PHASES AND GAMMA'-SINGLE-PHASES

Single crystals of the commercial nickel-base superalloy NIMONIC 105 w ith four different orientations have been compression tested in the te mperature range 600-1150 K. NIMONIC 105 is strengthened by fine, coher ent, shearable, homogeneously distributed precipitates of the L1(2)-lo ng-range ordered gamma'-phase (47 vol.%). The same investigations were undertaken for single crystals of the two constituent phases: L1(2)-o rdered, intermetallic single-phase gamma' and disordered single-phase f.c.c. gamma-matrix. Their compositions were those of the two equilibr ium phases of NIMONIC 105. The CRSS of NIMONIC 105 and of the gamma'-p hase were anisotropic in the whole temperature range. The CRSS of the gamma-matrix was isotropic. The interpretation of the anisotropy of NI MONIC 105 follows that of single-phase L1(2)-ordered gamma'. (C) 1997 Elsevier Science S.A.