Sequence of distinct microyielding stages of the monocrystalline nickel-base superalloy CMSX-6 at high temperatures
- The microyielding behaviour of the monocrystalline nickel-base superalloy CMSX-6 has been studied experimentally in tensile tests up to small strains at 900 °C, 1000 °C and 1100 °C and by transmission electron microscopy of the deformed specimens. Inspection of the microyielding stress-strain curve with highly resolved plastic strain showed four distinct stages of deformation at the lowest temperature (900 °C) but not at the two higher temperatures. By considering the superposition of the external stress with the original coherency stresses and with the deformation-induced internal stresses and by inspection of the electron micrographs, these deformation stages could be assigned to successive dislocation glide processes in the horizontal and vertical -channels and, finally, in the ′-particles.