Effect of Alternating Bending on Texture, Structure, and Elastic Properties of Sheets of Magnesium Lithium Alloy

Brokmeier²,

et al. 2020

EEJP

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.

Section: Eejp 1 (2020)mentioning

confidence: 99%

Section: Eejp 1 (2020)mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Effect of Kind of Deformation on Young's Modulus, Damage Parameter, Texture and Structure of Alloy Mg – 5% Li (wt)

Brokmeier²,

et al. 2020

EEJP

“…The alternating bending render most significant impact on the structural parameters and mechanical properties, which are sensitive to small deformations during tensile tests. These are texture, yield stress and twins [6,7]. The texture in [6,7] was represented using inverse pole figures (IPF) of the direction (ND) to the rolling plane (IPF ND).…”

mentioning

confidence: 99%

Elastic Properties of Alloy ZE10 Sheets Evaluation by Kerns Texture Parameters

Savchuk

et al. 2021

EEJP

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.

Single crystal characteristics of the Mg - 5% Li alloy, found from the polycrystalline experimental data and the Kearns texture parameters

Sovkova

et al. 2022

Phys. Chem. Solid St.

This work aimed to experimentally determine of the Kearns texture parameters, elastic moduli, mechanical properties (ultimate tensile strength and yield strength) of sheets of an alloy of Mg 5 wt. % Li after various types of processing: 1) extrusion at 350 ° C through a rectangular die; 2) rolling with a change in its direction by 90° and intermediate annealing at 350°C after each pass; 3) after the subsequent alternating bending (AB) by 0.5; one; 3 and 5 cycles and evaluation of the elastic and mechanical properties of the corresponding single crystal of the alloy under study using the indicated data. The moduli of elasticity and strength characteristics of the studied polycrystalline samples were determined in the rolling direction (RD) and transverse direction (TD). Using the found parameters of the Kearns texture and the elastic and mechanical properties of the sheets, the values of the elastic modules and the ultimate strength and yield strength of the single crystal of the above alloy were estimated. The found modules of elasticity of a single crystal of an alloy Mg-5 wt. % Li deviate from their values found in previous studies by no more than 7.5%. Elastic modules and strength characteristics of the studied samples of magnesium alloy Mg 5 wt. % Li calculated from the single crystal data deviate from the experimental data by no more than 10%.