Research on adiabatic shear failure character of pure copper and aluminum bronze based on empirical electron theory

Abstract

The valence electron structure (VES) parameters affecting adiabatic shearing failure under high speed impact load using split Hopkinson pressure bar (SHPB) were studied by empirical electron theory (EET) of solids and molecules. There is a problem of multiple solutions about VES parameters in EET. The statistics values of VES parameters related to adiabatic shearing sensitivity were calculated to substitute for the most probable value among the multiple solutions according to the view that the microstate statistics values can reflect the macro physical quantity. The research shows that the adiabatic shearing sensitivity is growing with the rise of the statistics value of bond energy of the strongest covalent bond, and is decreasing with the rise of the statistics value of the lattice electron number. The statistics value of bond energy of the strongest covalent bond in aluminum bronze (QAl9-4) is larger than that in pure copper, and the statistics value of the lattice electron number in QAl9-4 is smaller than that in pure copper. Therefore, QAl9-4 is prone to adiabatic shearing failure, and the grains were only elongated due to the large deformation for pure copper without any adiabatic shear band (ASB). It is of great significance for the selection and design of material with different adiabatic shearing sensitivity to research the effect of alloy elements on adiabatic shearing sensitivity from the electronic structure perspective.