Shock resistance capabilities of nickel crystal containing helium nanobubbles

Abstract

It has been revealed in previous studies that helium bubbles have a damaging consequence on the load bearing capabilities of nickel. Shock resistance is the key characteristic of structural materials used in the construction of a nuclear reactor. Herein, atomistic simulations were performed to study the dynamic shock resistance capabilities of single crystal Ni impregnated with helium bubble. The effect of the geometrical configuration of helium bubble on a nickel crystal, which acts as a substrate in which the bubble is lodged, when subjected to shock loading, was studied. It was concluded from the atomistic simulations that the presence of helium bubble with a higher concentration of helium atom leads to a reflection of shock front energy from the shock path. The diameter of the helium bubble at the same concentration of He (the ratio of He atoms to the vacancy created by deleting Ni atoms) is less critical for the shock resistance capabilities of Ni crystal. At lower values of shock impact, the deformation is mainly controlled by dislocation emission, whereas at higher impact velocities, the phase transformation from FCC to BCC is the primary mode of deformation. The analysis presented in this article will help in elucidating the shock resistant capabilities of Ni facing challenges of transmutation.