Compression Behavior and Mechanical Modeling of Nanocrystalline Ni under High Strain Rate Loading

Abstract

To investigate mechanical properties and understand deformation mechanisms of nanocrystalline materials under high strain rate, the dynamic compression tests for nanocrystalline Ni bulk prepared by high-energy ball milling and hot-pressure sintering were carried out at different high strain rate on Hopkinson bar and a mechanical modeling based on deformation mechanism under high strain rate loading was developed. The experimental results indicate that the nanocrystalline Ni sample has higher strength and good ductility and the strength of the sample increased with the increasing strain rate. Meanwhile, The predictions by the mechanical modeling based on mechanism of dislocation gliding and grain boundary sliding at high strain rates show good agreements with the experimental data.