The response of the intermetallic compound Ni3Al to one-dimensional shock loading.

The shock response of the intermetallic compound Ni3Al (doped with boron to enhance ductility) has been investigated to determine equation of state and shock induced mechanical properties, and the response is compared to that of pure nickel. Examination of the Hugoniot data suggests that the Ni3Al has a higher compressibility than pure nickel. Elastic precursor decay has been observed, although due to the limited number of specimens available, we were not able to determine the point where the elastic amplitude became stable. Spall and shear strengths were observed to increase to a peak value (at a shock stress of between 6 and 7 GPa) before dropping again. We believe that this may be due to increasing amounts of damage behind the shock front as shocks of increased stress are applied. In a similar manner, spall strength was observed to decrease with pulse duration, again, most likely due to damage accumulating behind the shock front. Finally, it was observed that this material was brittle under all shock loading conditions studied in this investigation. We have proposed, due to the extremely high dislocation velocities imposed by the shock induced strain rates, that boron has effectively been removed from dislocations and hence cannot enhance ductility. [ABSTRACT FROM AUTHOR]