On the mechanisms of nucleation and subsequent development of the PLC bands in an AlMg alloy

The nucleation and subsequent development of the Portevin-Le Chatelier bands during tensile deformation in a binary AlMg alloy was investigated by digital image correlation technique. following states material were employed for current investigation: coarse-grained (CG), fine-grained (FG) after equal channel angular pressing (ECAP), severely strained (SS) ECAP followed cold rolling. Special attention paid to an embryo band maximizing contrast images. Particular spatiotemporal patterns three different conditions, testifying initiation having wedge shape on lateral surface specimen, obtained at high intermediate strain rates. evaluation serration amplitude velocity showed that dependence these values consists two stages (the linear growth-up/drop stage steady-state stage) CG materials only one FG materials. always occurs according mixed mechanism, which thickening slows down with decrease rate.