Browsing by Author "Tolkushkin A.O."

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    ANALYSIS OF THE TECHNOLOGICAL PROCESS OF FORGING WORKPIECES IN STEP-WEDGE STRIKERS USING FEM MODELING
    (2022-01-01) Volokitin A.V.; Naizabekov A.B.; Panin E.A.; Tolkushkin A.O.; Koinov T.A.
    In this paper, finite element modeling of the forging process in step-wedge strikers of two different configurations was carried out. During the analysis of the results of the shape change and the parameters of the stress-strain state, it was found that the configuration with a wedge and a depression in the cross section is the best option. The microstructure evolution of the metal was simulated during its deformation in step-wedge-shaped strikers of the optimal configuration. For comparative analysis, models with variable values of geometric and technological parameters were studied. It was found that the angle of the junction of the wedge and the depression, as well as the heating temperature of the workpiece, have a significant effect on the intensity of grinding of the initial grain size. The change in the strain rate has a negligible effect on the change in the microstructure. Varying the values of the friction coefficient at the contact of the workpiece and the tool does not affect the intensity of grinding of the initial grain size
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    Assessment of a new equipment for mechanical testing of materials by a torsion
    (2020-01-01) Bogatov A.A.; Shvarts D.L.; Tolkushkin A.O.; Lezhnev S.N.; Naizabekov A.B.; Yordanova R.M.
    The paper presents the results of an assessment of a new equipment for cylindrical samples testing by a unidirectional and an alternating torsion. A computer simulation of the unidirectional torsion process is carried out to choose the optimal shape of the working part of the test samples. A recommendation on the use of a specific samples configuration is given based on the results of a comparative analysis of the distribution of the stress strain state indicators along the length of the working part. A series of experiments on a torsion of aluminum samples with a different rotation speed and an amplitude of the alternating deformation is carried out. Graphs of the torque during the test of each sample depending on the strain rate and the strain amplitude during the alternating torsion are constructed in accordance with the experimental sensor data.
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    Development and research of the new forging technology of billets in the step-wedge dies
    (2019-01-01) Tolkushkin A.O.; Lezhnev S.N.; Naizabekov A.B.; Panin E.A.; Yordanova R.M.; Zhumagaliyev D.R.
    The article describes the concept of a new forging method of billets with square and rectangular cross-section in dies, which design allows to develop shear and alternating deformation in the deformable metal. A computer simulation of the billet drawing process in the step-wedge dies of two configurations was carried out by the finite element method. A comparative analysis of the stress-strain state showed that the use of the configuration of stepwedge dies with a wedge on the top die and a cavity on the bottom die by the distribution character of the stressstrain parameters is the best option for the implementation of the drawing process of rectangular billets. However, during the deformation in the second configuration dies with a wedge on the top die and a wedge-shaped cavity on the bottom die, respectively, the load force is greater than during deformation in the dies of first configuration with the dies having only wedge protrusions, due to the smaller contact area of the tool with the billet. Experimental studies have shown that after the deformation of billets in step and step-wedge dies of both configurations there is an uniform refinement of the original cast metal structure throughout the whole volume, but the use of step-wedge dies in both cases provides a more intensive refinement of the cast structure for one cycle.