Formation of adiabatic shear bands in the fatigued copper single crystal deformed at high strain rate

The microstructures of the primary and fatigued copper single crystals deformed at high strain rate were studied by Split-Hopkinson pressure bar (SHPB) and SEM. The results indicate that it is difficult to form the adiabatic shear bands (SBs) for the primary copper single crystal but it is easy for fatigued copper single crystal deformed at high strain rate. Persistent slip bands (PSBs) and stress concentration induced by shock wave are the main reasons to form the adiabatic SBs. The spacing and width of the adiabatic SBs decrease with increasing strain rates.