Effect of deformation by extrusion, rolling after extrusion (in combination with annealing and changing the rolling direction), and subsequent alternating bending (AB) with the number of cycles 0.5, 1, 3, and 5 on the elastic modulus (E), damage accumulation parameter (damage parameter ω), crystallographic texture, and substructure parameters of the binary Mg-5%Li alloy have been studied. The damage parameter (0 ≤ ω ≤ 1), which is interpreted as the relative reduction in the effective load-bearing cross-sectional area due to damage accumulation, was found by the change in the elastic modulus after various above types of deformation. At this, we used to compare equivalent deformation and equivalent elastic energy models. The substructure parameters (crystalline domains sizes D, lattice distortion ε, dislocation density ρ) were estimated by analyzing the physical broadening of the lines diffraction on the crystal lattice of studied alloy of the penetrating hard X-ray synchrotron radiation. It was found that in the studied alloy, sheet forms a texture, at which the hexagonal prism axis is 90° deviated from the normal direction (ND) to the sheet up to transverse direction (TD) after extrusion of the ingot at 350°C in combination with its further rolling in the direction of extrusion axis (rolling direction RD) to a thickness of 4.5 mm and annealing at 350°C after each pass. At this the crystallographic directions and coincide with RD. The texture, at which the hexagonal prism axis is deviated from ND to TD by angles ranging from 15 to 70° (unlike from texture of basal type of the pure magnesium) is formed after further rolling of studied alloy to a thickness of 1 mm with the changing of the RD on 90° in combination with annealing at 350°C after each pass. The crystallographic direction coincides with RD. The anisotropy of above mentioned characteristics was found. Correlation and regression analysis showed that the anisotropy and the values of E, D, ε, and ρ, are decreased, and the values of ω are increased with an increase of alternating bend cycles’ number. It is shown that changes in the above characteristics are mainly due to the crystallographic texture formed during thermomechanical processing and subsequent alternating bending of Mg-5%Li alloy sheets, which is confirmed by data of correlation and regression analysis.
The ZE10 magnesium alloy with the rare-earth metal additives, which contribute to a better forming of the alloy, was used as studied material. The ZE10 magnesium alloy with the rare-earth metal additives, which contribute to a better forming of the alloy, was used as studied material. Sheet material is usually straightened on roller levelers to relieve residual stresses and improve flatness. The metal is subjected to alternating deformation by bending when straightening. The changes in the structure, crystallographic texture and, as a result, physical and mechanical properties occur in the metal are often not taken into account in the future. The elastic modulus is an important parameter, for example, in the production of products using bending. In this work, the elastic modulus of sheets of magnesium alloy ZE10 was estimated in three main directions. A starting sheet was obtained by extruding an ingot, then rolling in the longitudinal direction and then rolling with a change in direction by 90° after each pass in combination with heating to 350°C. The original sheets were subsequently subjected to alternate folding. Evaluations were made of the elastic modulus of the original sheet, as well as the sheets after 0.5, 1.0, 3.0 and 5.0 alternating bending cycles. To estimate the elastic modulus, we used the Kearns texture parameters , which we calculated from the inverse pole figures, as well as the elastic constants of the single crystal of the ZE10 alloy found by us. The maximum deviation of the calculated and experimental values of the elastic modulus did not exceed 5.2%. Strong correlations and quadratic regression equations have been established between the values of the elastic modulus, mechanical characteristics (tensile strength, yield stress, elongation), on the one hand, and the above-mentioned parameters of the Kerns texture, on the other hand. The approximation reliability coefficients are 0.76 - 0.99.
The effect of electrons irradiation with an energy of E = 10 MeV and a dose of D = 5·1019 сm–2 on the structure evolution and creep of alloy VT1-0 in initial and nanostructured states obtained by the IPD method has been stud-ied. It is shown that, the deformation nanostructure of VT1-0 is resistant to subsequent deformation under creep conditions at T = 20 °C and is destroyed at T = 350 °C due to the development of recrystallization processes. Irradi-ation by electrons with an energy of E = 10 MeV and a dose of D = 5·1019 сm-2 has slightly effect on the mechanical characteristics of VT1-0, both in initial and nanostructured states, but leads to the conservation and stabilization of the nanostructure during creep at T = 20 °C and to the deceleration of the process of structure transformation at T = 350 °C as a result of a decrease in the level of internal stresses.
Crystallographic texture and microstructure of low-alloyed steel after twist extrusion (TE) and subsequent cold rolling along and across the TE axis were studied. The double axial cylindrical texture with axes ⟨110⟩ and ⟨100⟩ parallel to the TE axis and the vortexlike microstructure are formed in the steel during the TE. The subsequent rolling of extruded steel along the TE axis promotes the forming of typical steel rolling texture as well as the microstructure with elongated grains in rolling direction. Typical steel rolling texture as well as the equiaxed microstructure is formed in extruded steel after rolling in the direction transverse to the TE axis. The mechanisms of formation of the texture are discussed.
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