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 25° and 50° are the preferred locations for intergranular damage localization.