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Problem Statement (Relevance): The paper describes some features and prospective benefits of deformation by methods of drawing with shear (SD) and high pressure torsion (HPT) in a temperature range of dynamic strain aging (DSA) effect, which allow receiving a high complex of physical and mechanical properties. Objectives: The study aims to investigate and analyze features of the structure formation with the combined application of severe plastic deformation (SPD) and the DSA effect during deformation by drawing with shear and high pressure torsion, to establish patterns of the gradient structure formation. Methods Applied: 1. Computer simulation in Deform 3D software to investigate the stress-strain state on materials with various types of a crystalline lattice: copper grade M1 (FCC), Steel 10 (BCC) and titanium VT1-0 (HCP) and a further comparison with experimental results. 2. Microhardness measurement 3. Scanning and transmission electron microscopy. Originality: This research resulted in investigation of the combined effect of the DSA effect and SPD on the gradient structure formation and mechanical properties of metals with various crystalline lattices. Findings: the paper presents the results of the study of the structure formation during non-monotonous plastic deformation of the alloys (steel 10, copper and titanium) with various crystalline lattice types by SD, as well as ECAP and HPT of low-carbon steel in the temperature range of the DSA effect. Deformation mechanisms and features of the deformation behavior on a mesoscopic scale under various deformation treatment modes are analyzed. The temperature range of the DSA effect in steel 10 under ECAP and the fact of the gradient structure formation under HPT are established. Practical Relevance: The study helped to obtain data that can be used to choose the optimal deformation treatment mode with the DSA effect.

Microstructure, properties, and failure characteristics of medium-carbon steel subjected to severe plastic deformation Marina V Karavaeva, Svetlana K Kiseleva, Marina M Abramova et al. The structural parameters and the nature of distribution of the plastic deformation intensity were investigated. Higher efficiency of the drawing process with shear was revealed in terms of strain intensity accumulation. A comparative analysis of structural changes and microhardness distribution over the bulk of samples produced by the investigated methods was conducted. The repeatability of the stress-strain state parameters obtained through physical and mathematical modeling was shown. The analysis of the obtained results leads to the conclusion that the use of drawing with shear is advanced for the production of samples and billets with high strength and sufficiently high ductility by creating a gradient structure.Severe plastic deformation (SPD) is one of the most effective techniques to enhance the physical and mechanical properties of metallic materials via refining the structure to obtain the ultrafine-grained (UFG) and nanocrystalline (NC) states. For the formation of UFG and NC structures, complex deformation schemes are usually used: high pressure torsion, equal channel angular pressing, screw extrusion, etc. [1][2][3]. Despite the differences in loading conditions, all these schemes have one thing in common -the structure is refined due to active shear deformation of the metal under the combined effect of compression and tension. Further development of SPD techniques implies the elaboration of combined loading schemes with a mandatory use of shear deformation.The most well-known and widespread scheme of simple shear is free torsion [4]. Combining the scheme with reduction may be promising to disperse the structure and, as a result, to enhance mechanical properties.In recent years the methods of surface deformation treatment have been provoking interest. Among them are the known methods of forging [5], surface friction [6], ultrasonic treatment [7], and others, and also the methods developed not so long ago -ECA broaching and shear drawing [8,9].In the present paper we study the influence of two different loading schemes -conventional drawing and shear drawing -on the change in the deformation intensity and corresponding transformation of the structure that occurs in low-carbon steel under this treatment, and also to determine the relationship between these changes and mechanical characteristics.Additionally we propose here to perform an assessment of the severe plastic deformation intensity using numerical modeling, which would allow comparing the calculation results with the observed changes in the structure and properties.

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