scholarly journals Flow Stress Modelling and 3D Processing Maps of Al4.5Zn4.5Mg1Cu0.12Zr Alloy with Different Scandium Contents

2021 ◽  
Vol 11 (10) ◽  
pp. 4587
Author(s):  
Maxim G. Khomutov ◽  
Andrey V. Pozdniakov ◽  
Alexander Yu. Churyumov ◽  
Ruslan Yu. Barkov ◽  
Alexey N. Solonin ◽  
...  
Keyword(s):  
Flow Stress ◽  
Deformation Behaviour ◽  
Three Dimensional ◽  
Processing Maps ◽  
Hollomon Parameter ◽  
Stability Diagrams ◽  
Power Dissipation Efficiency ◽  
3D Processing ◽  
Hot Deformation Behaviour ◽  
Flow Stress Model

The hot deformation behaviour of an Al4.5Zn4.5Mg1Cu0.12Zr based alloy with 0.05, 0.1 and 0.15% Sc was investigated at temperatures between 300–450 °C and a strain rate of 0.1–15 s−1. The materials constants of a flow stress model based on the Zener-Hollomon parameter were determined (AARE was 5.8%). Three-dimensional processing maps were established by combining power dissipation efficiency and flow stability diagrams. Based on processing maps analysis and microstructures investigations, the optimal deformation parameters were determined as a temperature range of 350–400 °C and strain rates of 0.1–1 s−1 for the alloys with 0.05% and 0.1% Sc, and 0.1 s−1 for the alloy with 0.15% Sc.

Hot Deformation Behaviour and Microstructure in Al-Cu-Li Alloy Containing Small Amount of Ag and Mg

2006 ◽  
Vol 519-521 ◽  
pp. 1925-1930 ◽  
Author(s):  
Zhi Guo Chen ◽  
Zi Qiao Zheng ◽  
Dong Feng Han
Keyword(s):  
Flow Stress ◽  
Hot Deformation ◽  
Deformation Temperature ◽  
Deformation Behaviour ◽  
Flow Characteristics ◽  
Hollomon Parameter ◽  
Transmission Electron ◽  
Deformation Behaviors ◽  
Hot Deformation Behaviour ◽  
Peak Value

The hot deformation behaviors and microstructure in Al-Cu-Li alloy containing small amount of Ag and Mg were investigated by transmission electron microscopy and isothermal compression tests.When the strain rate is 0.1, 0.01 and 0.001s-1(the deformation temperature within the range of 360-520􀀀 ) and 1 s-1(deformation temperature 520 􀀀 )respectively, the flow stress decreases after a peak value, showing dynamic recrystallization,while the steady-state flow characteristics exist on the other deformation conditions. The flow stress of Al-Cu-Li-Mg-Ag alloy during hot deformation can be expressed by a Zener-Hollomon parameter in the hyperbolic-sine function with the hot deformation activation energyDH of 250.45kJ/mol. The dislocations may climb with support from many vacancies generated during hot deformation, thus forming lots of helical dislocations. The dynamic precipitation and successive dynamic particles coarsening during hot compression have been assumed to be responsible for further flow softening when deformed at low strain rates.

scholarly journals Correlation among the Power Dissipation Efficiency, Flow Stress Course, and Activation Energy Evolution in Cr-Mo Low-Alloyed Steel

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3480
Author(s):  
Petr Opěla ◽  
Ivo Schindler ◽  
Petr Kawulok ◽  
Rostislav Kawulok ◽  
Stanislav Rusz ◽  
...  
Keyword(s):  
Activation Energy ◽  
Flow Stress ◽  
Power Dissipation ◽  
Hot Compression ◽  
Alloyed Steel ◽  
Approximation Procedure ◽  
Processing Maps ◽  
Energy Evolution ◽  
Power Dissipation Efficiency ◽  
Low Alloyed Steel

In the presented research, conventional hot processing maps superimposed over the flow stress maps or activation energy maps are utilized to study a correlation among the efficiency of power dissipation, flow stress, and activation energy evolution in the case of Cr-Mo low-alloyed steel. All maps have been assembled on the basis of two flow curve datasets. The experimental one is the result of series of uniaxial hot compression tests. The predicted one has been calculated on the basis of the subsequent approximation procedure via a well-adapted artificial neural network. It was found that both flow stress and activation energy evolution are capable of expressing changes in the studied steel caused by the hot compression deformation. A direct association with the course of power dissipation efficiency is then evident in the case of both. The connection of the presence of instability districts to the activation energy evolution, flow stress course, and power dissipation efficiency was discussed further. Based on the obtained findings it can be stated that the activation energy processing maps represent another tool for the finding of appropriate forming conditions and can be utilized as a support feature for the conventionally-used processing maps to extend their informative ability.

Characterization of hot deformation behaviour of Zr2.5Nb0.5Cu using processing maps

1995 ◽  
Vol 218 (2) ◽  
pp. 247-255 ◽  
Author(s):  
J.K. Chakravartty ◽  
G.K. Dey ◽  
S. Banerjee ◽  
Y.V.R.K. Prasad
Keyword(s):  
Hot Deformation ◽  
Deformation Behaviour ◽  
Processing Maps ◽  
Hot Deformation Behaviour

scholarly journals Hot deformation behaviour of bamboo leaf ash–silicon carbide hybrid reinforced aluminium based composite

2020 ◽  
Vol 7 ◽  
pp. 17
Author(s):  
Kenneth Kanayo Alaneme ◽  
Saheed Adeoye Babalola ◽  
Lesley Heath Chown ◽  
Michael Oluwatosin Bodunrin
Keyword(s):  
Activation Energy ◽  
Flow Stress ◽  
Dynamic Recovery ◽  
Deformation Behaviour ◽  
Strain Rates ◽  
Dominant Deformation Mechanism ◽  
Bamboo Leaf Ash ◽  
Gleeble 3500 ◽  
Hot Deformation Behaviour ◽  
Microstructural Examination

Isothermal compression testing of BLA-SIC hybrid reinforced Aluminium composites was performed on Gleeble 3500 thermomechanical simulator under different deformation temperatures (300–400 °C) and strain rates (0.01–1 s‑1). The flow behaviour and the softening mechanisms were established using the trend of the stress-strain curves, activation energy and microstructural examination. The results showed that flow stress increased with decreasing temperature; but was not entirely strain rate sensitive − a characteristic identified in some Al 6XXX based metallic systems. Also, uncharacteristic flow stress oscillations were observed at strain rates of 0.01 and 0.1 s‑1 while steady state flow stress was observed at 1 s‑1. The hot working activation energy was ∼290.5 kJ/mol which was intermediate to the range of 111–509 kJ/mol reported in literature for various Al based composites. It was proposed that at strain rates of 0.01 and 0.1 s‑1, dynamic recrystallization and/or dislocations-reinforcements interactions were the dominant deformation mechanism(s), while at 1 s‑1, dynamic recovery was predominant.

scholarly journals Hot Deformation Behaviour of Mn–Cr–Mo Low-Alloy Steel in Various Phase Regions

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1255 ◽  
Author(s):  
Ivo Schindler ◽  
Petr Opěla ◽  
Petr Kawulok ◽  
Jaroslav Sojka ◽  
Kateřina Konečná ◽  
...  
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behaviour ◽  
True Strain ◽  
Coarse Grained ◽  
Peak Strain ◽  
Compression Tests ◽  
Wide Range ◽  
Hot Deformation Behaviour

The deformation behaviour of a coarse-grained as-cast medium-carbon steel, alloyed with 1.2% Mn, 0.8% Cr and 0.2% Mo, was studied by uniaxial compression tests for the strain rates of 0.02 s−1–20 s−1 in the unusually wide range of temperatures (650–1280 °C), i.e., in various phase regions including the region with predominant bainite content (up to the temperature of 757 °C). At temperatures above 820 °C, the structure was fully austenitic. The hot deformation activation energies of 648 kJ·mol−1 and 364 kJ·mol−1 have been calculated for the temperatures ≤770 °C and ≥770 °C, respectively. This corresponds to the significant increase of flow stress in the low-temperature bainitic region. Unique information on the hot deformation behaviour of bainite was obtained. The shape of the stress-strain curves was influenced by the dynamic recrystallization of ferrite or austenite. Dynamically recrystallized austenitic grains were strongly coarsened with decreasing strain rate and growing temperature. For the austenitic region, the relationship between the peak strain and the Zener–Hollomon parameter has been derived, and the phenomenological constitutive model describing the flow stress depending on temperature, true strain rate and true strain was developed. The model can be used to predict the forming forces in the seamless tubes production of the given steel.

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