EFFECT OF A LONG-TERM PRIOR AGING ON THE TENSILE BEHAVIOR OF A HIGH PERFORMANCE SINGLE-CRYSTAL SUPERALLOY

The influence of long-term aging heat treatments on the tensile behavi our of <001> single crystals of the MC2 nickel-based superalloy was in vestigated at room temperature, 650 and 950 degrees C. The precipitati on of brittle particles of a W-rich mu phase did not induce any delete rious effect on the tensile strength and ductility. The decrease in yi eld strength and the increase in ductility were attributed to the coar sening of the gamma' strengthening particles which promotes by-passing of the precipitates by matrix dislocations and the homogeneization of deformation.