In situ deformation experiments on a γ/γ′ superalloy Strengthening mechanisms

Through in situ straining experiments performed at 850 °C, on a γ/γ′ MC2 superalloy in a transmission electron microscope (TEM), the elementary mechanisms that control deformation were identified. On the recorded dynamic sequences, it is shown that deformation preferentially localizes in channels perpendicular to the [100] traction axis. Expanding from small loops, the creation and propagation of dislocations is observed. Both cross slip and climb events are observed on the moving dislocations which promote a tridimensionnal workhardening of these channels.