Phase transformations induced by pulsed shock-wave loading in a single crystal of the nickel super-alloy were studied. The crystal was loaded by impact with a steel plate (the maximum pressure on the sample surface was 100GPa, and the pulse duration was 10μs) and by the deceleration of explosion products at an obstacle (the maximum pressure was 20GPa, and the pulse duration was 10μs). Depending on the loading conditions, various pressure-drop gradients behind the shock front were realized. After loading at 20GPa, the crystal has a high dislocation density; after loading at 100GPa, a banded structure with misorientation bands directed along the <111> directions was formed. X-ray diffraction, neutron diffraction, and high-resolution transmission electron microscopy of the crystal subjected to shock-wave loading revealed an L12 → D022 phase transformation. Deformation micro-twins were observed near micro-cracks in the D022 phase.

Study of Phase Transformations in Ni3Al Superalloy after Shock-Wave Loading. Kazantseva, N.V., Greenberg, B.A., Shorokhov, E.V., Pirogov, A.N., Dorofeev, Y.A.: Physics of Metals and Metallography, 2005, 99[5], 535-44