EXPERIMENTAL STUDY OF THE STRUCTURE OF SHOCK WAVES IN A COMPRESSED POWDER OF NIKEL NANOPARTICLES

Abstract

Aim. Features of propagation of shock compression waves in samples of compressed nickel nanoparticles have been studied for the first time by laser interferometry under uniaxial loading conditions at relatively low pressures of 1.7 and 4.1 GPa. Methodology. Shock wave profiles of a compressed nickel nanopowder loaded by a one-dimensional shock compression wave are measured by a laser interferometry method. Results. Shock wave profiles and points of the shock Hugoniot of the material are obtained. The Hugoniot elastic limit is determined to be 0.48 GPa. Research implications. It is found that shock wave profiles of pressed nickel nanoparticles have a complex multi-stage structure in which the precursor wave is clearly distinguished. It is shown that the compression wave profile can be described by multiple reflection of the precursor wave from a sample surface and an oncoming plastic shock wave. It is established that in the range of studied pressures, the sample thickness and the loading regime determine the process of shock compression. It is demonstrated that the difference between the states of matter behind the plastic shock wave front before the first precursor reflection and after the last reflection is significant.