Effect of a long-term prior aging on the tensile behaviour of a high-performance single crystal superalloy

The influence of long-term aging heat treatments on the tensile behaviour of single crystals of the MC2 nickel-based superalloy was investigated at room temperature, 650 and 950°C. The precipitation of brittle particles of a W-rich µ phase did not induce any deleterious effect on the tensile strength and ductility. The decrease in yield strength and the increase in ductility were attributed to the coarsening of the γ' strengthening particles which promotes by-passing of the precipitates by matrix dislocations and the homogeneization of deformation