Influence of boundary structure and near neighbor crystallographic orientation on the dynamic damage evolution during shock loading

Abstract

The role of crystallographic orientation on damage evolution in ductile metals during shock loading has been investigated. By utilizing large-grained copper specimens, it has been shown that the development of intragranular damage, in the form of void growth and coalescence, is influenced by the grain orientation with respect to the applied load. Additionally, strain incompatibility and the inability to promote transmission or activation of secondary dislocation slip across a grain boundary, are proposed as the likely cause for intergranular failure. Finally, the free surface velocity profiles of each grain, specifically the decay of the oscillations after the pull-back, correlated well with the amount of damage measured within the respective grain.

Keywords:

• damage evolution
• EBSD
• Taylor factor
• shock loading

Acknowledgements

Los Alamos National Laboratory is operated by LANS, LLC, for the NNSA of the US Department of Energy under Contract DE-AC52-06NA25396. This work was supported by LDRD-DR20100026. Work by EKC and CPT has been supported by the Office of Basic Energy Sciences, Energy Frontier Research, Center for Materials at Irradiation and Mechanical Extremes (CMIME). The authors wish to thank D. Byler for providing the samples.