Kinematics of slip-induced rotation for uniaxial shock or ramp compression
When a metallic specimen is plastically deformed, its underlying crystal structure must often rotate in order to comply with its macroscopic boundary conditions. There is growing interest within the dynamic compression community in exploiting x-ray diffraction measurements of lattice rotation to inf...
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| 格式: | Journal article |
| 语言: | English |
| 出版: |
AIP Publishing
2021
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| 总结: | When a metallic specimen is plastically deformed, its underlying crystal structure must often rotate in order to
comply with its macroscopic boundary conditions. There is growing interest within the dynamic compression
community in exploiting x-ray diffraction measurements of lattice rotation to infer which combinations of
plasticity mechanisms are operative in uniaxially shock- or ramp-compressed crystals, thus informing materials
science at the greatest extremes of pressure and strain rate. However, it is not widely appreciated that several
of the existing models linking rotation to slip activity are fundamentally inapplicable to a planar compression
scenario. We present molecular dynamics simulations of single crystals suffering true uniaxial strain, and
show that the Schmid and Taylor analyses used in traditional materials science fail to predict the ensuing
lattice rotation. We propose a simple alternative framework based on the elastoplastic decomposition that
successfully recovers the observed rotation for these single crystals, and can further be used to identify the
operative slip systems and the amount of activity upon them in the idealized cases of single and double slip. |
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