Statistics of weak grain boundaries for spall damage in polycrystalline copper

Correlations between spall damage and local microstructure were investigated using polycrystalline copper samples via laser-driven plate impacts at low pressures. Electron backscattering diffraction was used to relate the presence of porosity to microstructural features such as grain boundaries and triple points. Preferred void-nucleation sites were identified in terms of their crystallography via statistical sampling in serial sectioned specimens. Results indicate that terminated twins and grain boundaries with misorientations between 25o and 50o are the preferred locations for intergranular damage localization.