Pure Cu single crystals irradiated at room temperature to low doses with 590MeV protons were deformed in situ in a transmission electron microscope in order to identify the basic mechanisms at the origin of hardening. Cu irradiated to 10−4dpa showed at room temperature a yield shear stress of 13.7MPa to be compared to the 8.8MPa of the unirradiated Cu. Irradiation induced damage consists at 90% of 2nm stacking fault tetrahedra, the remaining being dislocation loops and unidentified defects. In situ deformation revealed that dislocation–defect interaction could take several forms. Usually, dislocations pinned by defects bow out under the applied stress and escape without leaving any visible defect. From the escape angles obtained at 183K, an average critical stress of 100MPa was deduced. In some cases, the pinning of dislocations leads to debris that were about 20nm long, which formation could be recorded during the in situ experiment.

Dislocation Defect Interaction in Irradiated Cu. R.Schäublin, Z.Yao, P.Spätig, M.Victoria: Materials Science and Engineering A, 2005, 400-401, 251-5