A mathematical model for evolution of flow stress during hot deformation

Serajzadeh, S.

doi:10.1016/j.matlet.2005.05.065

Cited by 17 publications

(9 citation statements)

References 18 publications

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“…WH, DRV, and DRX play a vital role in microstructural changes of materials and their mechanical properties, which are explained in the later stages of this work. A rapid rise in the flow stress at the initial stage of extrusion might be attributed to the higher dislocation density as explained by Serajzadeh et al 12 Strain softening was observed at large strains in all the curves due to the dynamic softening after reaching PFS. The dynamic softening phenomenon of material increases with increasing deformation temperature and decreasing strain rate.…”

Section: True Stress-true Strain Curvementioning

confidence: 62%

“…Differences in activation energy (Q) between the present alloy and other Al alloys might be because of dislocation pinning effect, and due to the effect of DRV, DRX, and dynamic precipitation as explained in the microstructural evolution section (section "Microstructural Evolution during Hot deformation"). Natural logarithm can be taken on both sides of equation (5) to obtain equation (12) lnZ ¼ lnA þ nln sinh ar ð Þ ½…”

Section: Calculation Of Activation Energy (Q)mentioning

confidence: 99%

“…11 Hot deformation can affect the flow behavior, microstructure, and energy required for deformation through various metallurgical phenomena namely WH, DRV, and DRX. 12,13 Recent studies have shown that the general flow stress trend is decreased with increase in deformation temperature and decrease in the strain rate. [14][15][16][17][18] Sun et al 19 have explained and modeled the hot deformation of asextruded 7075 Al alloy.…”

Section: Introductionmentioning

confidence: 99%

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Hot deformation behavior and dynamic recrystallization constitutive modeling of Al–Cu–Mg powder compacts processed by extrusion at elevated temperatures

Bharath

Khanra

Davidson

2020

Proceedings of the Institution of Mechanical Engineers, Part L:

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The deformation behavior of Al–Cu–Mg sintered preforms has been investigated by extrusion in the temperature range of 450–550°C and strain rate range of 0.1–0.3 s−1, respectively. The aim of this study is to analyze the effect of initial preform relative density on the hot deformation behavior and to model and predict the flow stress of extruded samples using constitutive equations. The true stress–strain curves exhibit three stages of deformation, which represent work hardening, dynamic recovery, and dynamic recrystallization during deformation at different temperatures, strain rates, and initial preform relative densities of 70%, 80%, and 90%, respectively. The results show that the flow stress values are influenced by initial preform relative density, deformation temperature, and strain rate. Microstructural examination of extruded specimens has been performed by optical microscopy and scanning electron microscopy. Arrhenius-type constitutive equations are developed to predict the flow stress of hot-extruded powder metallurgy processed aluminum alloy (Al–4%Cu–0.5%Mg). Zener–Hollomon parameter is used to explain the relationship between peak flow stress, temperature, and strain rate in an exponential equation containing the deformation activation energy and material constants. Subsequently, the statistical indicators correlation coefficient ( R) and the average absolute relative error are assessed to confirm the validity of constitutive equations. The results indicate the experimental and predicted peak flow stress values are in good agreement, which indicate the accuracy and reliability of the developed model for powder metallurgy processed Al–4%Cu–0.5%Mg preforms.

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Section: True Stress-true Strain Curvementioning

confidence: 62%

Section: Calculation Of Activation Energy (Q)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Hot deformation behavior and dynamic recrystallization constitutive modeling of Al–Cu–Mg powder compacts processed by extrusion at elevated temperatures

Bharath

Khanra

Davidson

2020

Proceedings of the Institution of Mechanical Engineers, Part L:

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“…This effect is very important to study many metallurgical phenomena. For example, the difference in temperature affects the dynamic recrystallization and the dynamic recovery mechanisms; and as a result, the final microstructure changes between surface and center of strip [6,7,18]. In Fig.…”

Section: Modelling Results and Discussionmentioning

confidence: 99%

Thermal analysis of hot strip rolling using finite element and upper bound methods

Sadrnia

2009

Applied Mathematical Modelling

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a b s t r a c tThermal analysis of hot rolling process has been studied in this work. A finite element method has been coupled with an upper bound solution assuming, triangular velocity field, to predict temperature field during hot strip rolling operation. To do so, an Upwind PetrovGalerkin scheme together with isoparametric quadrilateral elements has been employed to solve the steady-state heat transfer equation. A comparison has been made between the published and the model predictions and a good agreement was observed showing the accuracy of the proposed model.

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“…Many material models are available to describe RX and recovery mechanisms [3][4][5][6]. Advanced models use constitutive dislocation-based equations capable of mapping the interaction of dislocation-based hardening, the RX cycle, grain size, recovery processes and the resulting viscoplastic flow behavior.…”

Section: Introductionmentioning

confidence: 99%

Modeling Material Flow Characteristics Over Multiple Recrystallization Cycles

Foster¹,

Lin²,

Farrugia³

et al. 2007

AIP Conference Proceedings

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The evolution of steel micro structure during multi-pass hot rolling processes may include several recrystallization (RX) stages. Assuming a sufficient dislocation density is present at the exit of the roll, RX will occur during the interpass time between rolling stages. This will result in the material reaching the next rolling stand in either a full recrystallized or part recrystallized state. In this study an equation set is proposed in which complex RX cycles may be modeled, including overlapping cycles. Other micro structure information such as grain size evolution may be mapped.

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A mathematical model for evolution of flow stress during hot deformation

Cited by 17 publications

References 18 publications

Hot deformation behavior and dynamic recrystallization constitutive modeling of Al–Cu–Mg powder compacts processed by extrusion at elevated temperatures

Hot deformation behavior and dynamic recrystallization constitutive modeling of Al–Cu–Mg powder compacts processed by extrusion at elevated temperatures

Thermal analysis of hot strip rolling using finite element and upper bound methods

Modeling Material Flow Characteristics Over Multiple Recrystallization Cycles

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