Issue 38

M. Sokovikov et alii, Frattura ed Integrità Strutturale, 38 (2016) 296-304; DOI: 10.3221/IGF-ESIS.38.40 301 Figure 8 : Time dependence of the free surface velocity in the area of plug formation and eject. a) b) Figure 9 : Rough surface relief corresponding to the plug shear in the specimen. a) rough region near the mirror region, b) rough region at a distance from the mirror region. The multiscale character of deformation processes taking place in samples subjected to dynamic loading was revealed by selective etching of transverse sections of deformed samples (Fig.10). For example, macroetching in the aqueous solution of 10 % hydrofluoric acid (HF) allowed us to determine the macrolines of the material flow (Fig.10a). Macroetching in the aqueous solution of 1 % NaOH indicates the presence of 15-20 thinner lines between the flow macrolines (Fig.10b). a) b) Figure 10 : Sample microstructure near the fracture surface for different levels: a) strain macrobands; b) strain microbands. Optical microscopy.