Dislocation/grain boundary interactions in ice crystals under creep conditions

Dislocation/grain boundary (GB) interactions in ice polycrystals have been studied in situ using synchrotron X-ray topography. GBs act both as sources of lattice dislocations and as obstacles to dislocation motion. Three key features are demonstrated in this paper: nucleation, glide and piling up of basal dislocations; nucleation and glide of non-basal dislocations; and slip transmission through a GB. The latter feature was observed only once in twenty five experiments.