Constitutive modeling of Mg–9Li–3Al–2Sr–2Y at elevated temperatures

Wei, Guobing; Peng, Xiaodong; Hadadzadeh, Amir; Mahmoodkhani, Yahya; Xie, Weidong; Yang, Yan; Wells, Mary A.

doi:10.1016/j.mechmat.2015.05.006

Cited by 51 publications

(19 citation statements)

References 26 publications

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“…The calculated value was lower than those of the rolled single α-phase Mg–Li alloy (211 kJ/mol) [ 24 ], as-cast LAZ532 (160 kJ/mol) [ 3 ], commercial AZ80 alloy (216 kJ/mol) [ 36 ], extruded-state α(Mg)–β(Li) duplex phase Mg–Li alloy (148 kJ/mol) [ 37 ], as-cast Mg–2 Zn–0.3 Zr–0.9 Y alloy (236.2 kJ/mol) [ 38 ], and as-cast Mg–3 Sn–Ca alloy (236 kJ/mol) [ 39 ]. Despite being related to the other Mg–Li alloys with α + β duplex phases or a single β -phase, the deformation activation energy in the presented work was higher than those of the as-cast α + β alloy (127 kJ/mol) [ 40 ], the as-cast single β -phase Mg–Li alloy (95 kJ/mol) [ 41 ], the as-cast Mg–8 Li–3 Al–2 Zn alloy modified with Zr (108 kJ/mol) [ 8 ], the as-cast Mg–9 Li–1 Zn alloy (127 kJ/mol) [ 42 ], the as-cast Mg–11.5 Li–1.5 Al alloy (95 kJ/mol) [ 43 ], the as-cast Mg–3 Sn–2 Al–1 Zn–5 Li (139 kJ/mol) [ 44 , 45 ], the as-cast Mg–9 Li–3 Al alloy with Sr addition (110 kJ/mol) [ 46 ], and as-cast LA43M (110 kJ/mol) [ 4 ].…”

Section: Resultsmentioning

confidence: 99%

Hot Deformation Treatment of Grain-Modified Mg–Li Alloy

et al. 2020

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In this work, a systematic analysis of the hot deformation mechanism and a microstructure characterization of an as-cast single α-phase Mg–4.5 Li–1.5 Al alloy modified with 0.2% TiB addition, as a grain refiner, is presented. The optimized constitutive model and hot working terms of the Mg–Li alloy were also determined. The hot compression procedure of the Mg–4.5 Li–1.5 Al + 0.2 TiB alloy was performed using a DIL 805 A/D dilatometer at deformation temperatures from 250 °C to 400 °C and with strain rates of 0.01–1 s−1. The processing map adapted from a dynamic material model (DMM) of the as-cast alloy was developed through the superposition of the established instability map and power dissipation map. By considering the processing maps and microstructure characteristics, the processing window for the Mg–Li alloy were determined to be at the deformation temperature of 590 K–670 K and with a strain rate range of 0.01–0.02 s−1.

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Section: Resultsmentioning

confidence: 99%

Hot Deformation Treatment of Grain-Modified Mg–Li Alloy

et al. 2020

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“…In order to predict the flow stress over a wide range of temperatures and strains, it is necessary to interpolate the obtained values by a certain continuous function. Strain-dependent material parameters are most often translated by a polynomial curve of a certain degree [30,31]. To select the polynomial degree correctly, we fitted obtained points by the polynomials from the 2nd to 7th order and based on the quality of fitting, represented by the coefficient of determination R 2 , the final decision for an appropriate equation selection could be made.…”

Section: Constitutive Modellingmentioning

confidence: 99%

Hot Deformation Process Analysis and Modelling of X153CrMoV12 Steel

Krbaťa

Eckert

Križan

et al. 2019

Metals

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Analysis of the high temperature plastic behavior of high-strength steel X153CrMoV12 was developed in the temperature range of 800–1200 °C and the deformation rate in the range of 0.001–10 s−1 to the maximum value of the true strain 0.9%. Microstructural changes were observed using light optical microscopy (LOM) as well as atomic force microscopy (AFM). The effect of hot deformation temperature on true stress, peak stress and true strain was evaluated from the respective flow curves. Based on these results, steel transformation was discussed from the dynamic recovery and recrystallization point of view. Furthermore, a present model, taking into account the Zener–Hollomon parameter, was developed to predict the true stress and strain over a wide range of temperatures and strain rates. Using constitutive equations, material parameters and activation energy were derived, which can be subsequently applied to other models related to hot deformation behavior of selected tool steels. The experimental data were compassed to the ones obtained by the predictive model with the correlation coefficient R = 0.98267. These results demonstrate an appropriate applicability of the model for experimental materials in hot deformation applications.

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“…Mainly featured by continuous dynamic softening, the flow stress decreases after peak stress smoothly until it becomes steady. During the steady stage, the dynamic recrystallization and work hardening achieve a new balance so that the flow stress no longer changes with the increase of the strain, and steady flow of material forms [24]. accompanied by dynamic softening, but work hardening is still the main deformation mechanism.…”

Section: Hot Compression Flow Behaviormentioning

confidence: 99%

Characterization of Hot Deformation Behavior and Processing Maps of Mg-3Sn-2Al-1Zn-5Li Magnesium Alloy

Guo

Xuanyuan

Lia

et al. 2019

Metals

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The dynamic microstructure evolution of Mg-3Sn-2Al-1Zn-5Li magnesium alloy during hot deformation is studied by hot compression tests over the temperature range of 200–350 °C under the strain rate of 0.001–1 s−1, whereafter constitutive equations and processing maps are developed and constructed. In most of cases, the material shows typical dynamic recrystallization (DRX) features, with a signal peak value followed by a gradual decrease. The value of Q (deformation activation energy) is 138.89414 kJ/mol, and the instability domains occur at high strain rate but the stability domains are opposite, and the optimum hot working parameter for the studied alloy is determined to be 350 °C/0.001 s−1 according to the processing maps. Within 200–350 °C, the operating mechanism of dynamic recrystallization (DRX) of Mg-3Sn-2Al-1Zn-5Li alloy during hot deformation is mainly affected by strain rate. Dynamic recrystallization (DRX) structures are observed from the samples at 300 °C/0.001 s−1 and 350 °C/0.001 s−1, which consist of continuous DRX (CDRX) and discontinuous DRX (DDRX). However, dynamic recovery (DRV) still dominates the softening mechanism. At the grain boundaries, mass dislocation pile-ups and dislocation tangle provide sites for potential nucleation. Meanwhile, flow localization bands are observed from the samples at 200 °C/1 s−1 and 250 °C/0.1 s−1 as the main instability mechanism.

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Constitutive modeling of Mg–9Li–3Al–2Sr–2Y at elevated temperatures

Cited by 51 publications

References 26 publications

Hot Deformation Treatment of Grain-Modified Mg–Li Alloy

Hot Deformation Treatment of Grain-Modified Mg–Li Alloy

Hot Deformation Process Analysis and Modelling of X153CrMoV12 Steel

Characterization of Hot Deformation Behavior and Processing Maps of Mg-3Sn-2Al-1Zn-5Li Magnesium Alloy

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