The present paper focuses on some recent achivements and problems in developing the severe plastic deformation methods to enhance properties of metals and alloys by means of optimization of formed nanostructures.

The investigation of the backpressure effect during equal-channel angular pressing (ECAP) on formation of ultrafine-grained (UFG) structure in pure copper has revealed that the increased hydrostatic pressure can contribute to formation of a more homogeneous microstructure with finer grains. ECAP with backpressure also exerts a favorable effect on strength and ductility characteristics of the UFG material.

This paper reports the results of investigation of mechanical behavior of the ultrafine-grained (UFG) Ti - 6Al - 4V alloy processed by equal-channel angular pressing (ECAP) and extrusion at temperatures in a range of 500 - 800 <$E symbol Р>C. The UFG alloy reveals superplastic behavior at relatively low temperatures down to 600 <$E symbol Р>C (elongation 240 %). The features of microstructure change of the UFG alloy under superplastic straining conditions that contribute to additional strengthening of the alloy are shown.

During the last decade severe plastic deformation (SPD) has become a widely known method of materials processing used for fabrication of ultrafine-grained materials with attractive properties. Nowadays SPD processing is rapidly developing and is on the verge of a transition from lab-scale research to commercial production. This paper focuses on several new trends in the development of SPD techniques for effective grain refinement, including those for commercial alloys, and presents new SPD processing routes to produce bulk nanocrystalline materials.

Исследованы особенности микроструктуры поверхностей излома и низкотемпературные механические свойства сверхмелкозернистого ELI-сплава Ti - 6Al - 4V, обработанного методом равноканального углового прессования, при квазистатическом одноосном растяжении и сжатии. Сравнены значения предела текучести и однородной деформации, полученные при температурах 300, 77 и 4,2 K для разных структурных состояний ELI-сплава Ti - 6Al - 4V с различным средним размером зерна и морфологией <$E alpha>- и <$E beta>-фаз. Исследовано статистическое распределение размеров ямок на поверхностях излома при различных структурных состояниях и температурах.