摘要:AbstractThe effect of severe plastic deformation (SPD) during cyclic extrusion (CE) on grain refinement and strain hardening in AlSiCu alloy is studied quantitatively.New experimental results are presented showing that the average of grain size decrease below 130nm, i.e. a nanocrystalline material is obtained. In the modelling part, the decrease in size of dislocation cells and micro bands is expressed in terms of the effective plastic strain defined such that strain rate reversals slow down its accumulation. Examples of microstructure of tested alloy severely deformed by cyclic extrusion are given as experimental results.