Sergey Lezhnev

Prof. Dr. Sergey Lezhnev

orcid

Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
10 September 2013 in Advanced Materials Research
Verified
Journal Article
Closed access
PDF file
SLSergey Lezhnev
Sergey Lezhnev
EPEvgeniy Panin
Evgeniy Panin
IVIrina Volokitina
Irina Volokitina
In the development of new technology forming the ultimate goal is increasing of productivity, expansion of range, creating a compact production, capable of rapid reconfiguration for mobile release of the new product. But the main purpose, of course, is improvement the quality of the source material. When used as a raw material of various grades of steel, non-ferrous metals and their alloys, the main aspect of quality improvement is increasing the strength characteristics. Often to increase the strength of deformable metal should be given reduced grain structure, up to subultra and even nano-level. There are several ways to obtain sub-ultra-fine-grain structure of metals and alloys, and one of those ways is a method of severe plastic deformation of the metal, implemented in the whole volume of the deformable metal.On the department "Plastic Metal Working" of Karaganda State Industrial University was previously developed and proposed a new method of combined rolling and pressing in equal-channel step die, which compared to conventional compression in the traditional equal-channel step die ensures the continuity of the process and removes the restrictions on the size of the original pieces. The essence of the method is that workpiece which is pre-heated to a temperature of the beginning of deformation is applied to the forming rolls, which due to contact friction forces captured it in roll gap and pushed through the channels of equal- channel step die. At the exit from the die installed a second pair of rolls, which pulls the workpiece from the die.In the research of the process were made theoretical studies, after which were received the empirical formulas to determine the rolling force in the rolls and pressing force in the matrix. Also were obtained formulas for the kinematic state of the process.Also conducted a simulation of the process in the software package Deform-3D, in which produced the picture of stress - strain state and analyzed the resulting force.In this work, laboratory studies were performed of the combined process. In particular, a laboratory experiment was conducted to implement the combined process of "rolling-compaction", whose main purpose was to research the effect of the scheme on the deformation changes in the microstructure and mechanical properties of the original pieces, made of aluminum alloy AK6.Research of the mechanical properties and microstructure of deformed aluminum billet by this way was found that the implementation of the combined process of "rolling-compression" increases strength properties of aluminum, and reduced plastic properties, and the original grain during deformation is reduced.

2 August 2019 in Physica Scripta
Verified
Journal Article
Closed access
PDF file
ANAbdrakhman Naizabekov
Abdrakhman Naizabekov
AAAlexandr Arbuz
Alexandr Arbuz
SLSergey Lezhnev
Sergey Lezhnev
EPEvgeniy Panin
Evgeniy Panin
IVIrina Volokitina
Irina Volokitina
The work is devoted to the problem of quantitative evaluation of the microstructure on the example of work with the TEM study of ultrafine-grained (UFG) austenitic steel for use in nuclear power. The material was obtained by radial-shear rolling and has different features of the structural structure of the cross section (from the periphery to the center), which makes it relevant to the correct assessment of the microstructure, taking into account all the features. This is difficult to do correctly, using only existing simple methods (average grain size, degree of grain misalignment, phase ratio) and most importantly, the results can not always be compared with each other. For a more objective and unambiguous assessment of different types of microstructure, a new qualimetric technique for quantitative quality analysis was developed. The new technique made it possible to make a more correct comparison of changes in the quality of the rod microstructure and to evaluate the effectiveness of the technology. According to the assessment, the greatest improvement is experienced by the central zone of the bar, from 0.13 to 0.43, that is, more than 3 times. At the same time, the quality growth of the peripheral region is low (only 1.29 times) and tends to slow down. This is due to the fact that with an increase in the degree of deformation there is no further refinement of the structure, but only improves its shape, becoming more uniform, as also evidenced by the values of the mean square deviation, showing the minimum spread of values. The resulting methodology for the qualimetric evaluation of quality can be used to create free open of image processing algorithms (e.g. MathLab), and for commercial products for quantitative metallographic analysis.

10 December 2018 in Journal of Materials Engineering and Performance
Verified
Journal Article
Closed access
PDF file
ANAbdrakhman Naizabekov
Abdrakhman Naizabekov
SLSergey Lezhnev
Sergey Lezhnev
EPEvgeniy Panin
Evgeniy Panin
IVIrina Volokitina
Irina Volokitina
AAAlexandr Arbuz
Alexandr Arbuz
IMIgor Mazur
Igor Mazur

1 September 2015 in Metal Science and Heat Treatment
Verified
Journal Article
Closed access
PDF file
ANAbdrakhman Naizabekov
Abdrakhman Naizabekov
SLSergey Lezhnev
Sergey Lezhnev
IVI. E. Volokitina
I. E. Volokitina

1 January 2014 in Procedia Engineering
Verified
Journal Article
Open access
SLSergey Lezhnev
Sergey Lezhnev
ANAbdrakhman Naizabekov
Abdrakhman Naizabekov
Andrey VolokitinAndrey Volokitin
Andrey Volokitin
VIVolokitina Irina
Volokitina Irina
The aim of this work is to study the influence of the combined process of “pressing-drawing” on the microstructure and mechanical properties of aluminum wire. Analysis of the results of the research has shown that the proposed combined method of deformation “pressing-drawing” has a significant advantage over the existing technology of production of aluminum wire. This method of deformation due to combination of two ways: by severe plastic deformation in equal channel step die and the process of drawing through a drawing die, allows obtaining aluminum wire with ultrafine-grained structure and a high level of mechanical properties, required size and shape of the cross section at a small number of cycles of deformation. Also would like to mention that this method of deformation in implementing it in production does not require significant economic investments, and substantial refitting of existing drawing mills

24 November 2017 in Physics of Metals and Metallography
Verified
Journal Article
Closed access
PDF file
SLSergey Lezhnev
Sergey Lezhnev
IVIrina Volokitina
Irina Volokitina
Andrey VolokitinAndrey Volokitin
Andrey Volokitin
The combined continuous pressing–drawing process is proposed after a comprehensive analysis of available plastic structure-forming techniques taking into account the promising trends in their developm