Factors influencing the development of ultrafine grained materials through severe plastic deformation

Equal-channel angular (ECA) pressing is a processing method which may be used to achieve substantial grain refinement in polycrystalline metals. Typically, metals subjected to ECA pressing have grain sizes in the submicrometer range. This paper considers the factors influencing the development of a homogeneous microstructure of equiaxed grains separated by high angle grain boundaries, including the pressing speed, the strain introduced on each passage through the die and the effect of specimen rotation between consecutive pressings.