Final Report LDRD 04-ERD-021

Bringa, E

Lawrence Livermore National Laboratory

关键词: Plastics;    Strain Rate;    X-Ray Diffraction;    36 Materials Science;    Compression;   

DOI  :  10.2172/902248
RP-ID  :  UCRL-TR-228484
RP-ID  :  W-7405-ENG-48
RP-ID  :  902248

美国|英语

来源: UNT Digital Library

【 摘 要 】

In this project, we performed experiments and simulations to establish constitutive models for plastic behavior and to determine the deformation mechanism of nanocrystalline materials at different grain sizes (<100 nm) and high strain rates (>10{sup 6}/s). The experiments used both laser-induced shocks and isentropic compression to investigate, for the first time, the high-strain-rate deformation of nanocrystalline Ni. Samples were characterized using transmission electron microscopy, nanoindentation, profilometry, and x-ray diffraction before and after loading. We validated constitutive models using both atomistic molecular dynamics and continuum simulations performed at the boundary of their current computational possibilities to match experimental scales.