Deformation Behavior and Precipitation Features in a Stretched Al–Cu Alloy at Intermediate Temperatures

Deformation behavior and precipitation features of an Al–Cu alloy are investigated using uniaxial tensile tests at intermediate temperatures. It is found that the true stress drops with the decreased strain rate or the increased deformation temperature. The number of substructures and the degree of grain elongation decrease with the raised temperature or the decreased strain rate. At high temperatures or low strain rates, some dynamic recrystallized grains can be found. The type of precipitates is influenced by the heating process before hot tensile deformation. The content and size of precipitates increase during tensile deformation at intermediate temperatures. As the temperature increases over 200 °C, the precipitation process (Guinier Preston zone (G.P. zones)→θ′′ phase→θ′ phase) is enhanced, resulting in increased contents of θ′′ and θ′ phases. However, θ′′ and θ′ phases prefer to precipitate along the {020}Al direction, resulting in an uneven distribution of phases. Considering the flow softening degree and the excessive heterogeneous precipitation of θ′′ and θ′ phases during hot deformation, the reasonable strain rate and temperature are about 0.0003 s−1 and 150 °C, respectively.

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Experimental and Numerical Investigations on Hot Deformation Behavior and Processing Maps for ASS 304 and ASS 316

High Temperature Materials and Processes ◽

10.1515/htmp-2017-0047 ◽

2018 ◽

Vol 37 (9-10) ◽

pp. 873-888 ◽

Cited By ~ 3

Author(s):

Nitin Kotkunde ◽

Hansoge Nitin Krishnamurthy ◽

Swadesh Kumar Singh ◽

Gangadhar Jella

Keyword(s):

Experimental Data ◽

Strain Rate ◽

Hot Deformation ◽

Deformation Behavior ◽

Constitutive Models ◽

Tensile Tests ◽

Uniaxial Tensile ◽

Processing Maps ◽

Hot Deformation Behavior ◽

Statistical Measures

AbstractA thorough understanding of hot deformation behavior plays a vital role in determining process parameters of hot working processes. Firstly, uniaxial tensile tests have been performed in the temperature ranges of 150 °C–600 °C and strain rate ranges of 0.0001–0.01s−1 for analyzing the deformation behavior of ASS 304 and ASS 316. The phenomenological-based constitutive models namely modified Fields–Backofen (m-FB) and Khan–Huang–Liang (KHL) have been developed. The prediction capability of these models has been verified with experimental data using various statistical measures. Analysis of statistical measures revealed KHL model has good agreement with experimental flow stress data. Through the flow stresses behavior, the processing maps are established and analyzed according to the dynamic materials model (DMM). In the processing map, the variation of the efficiency of the power dissipation is plotted as a function of temperature and strain rate. The processing maps results have been validated with experimental data.

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Tensile Deformation Behavior of 5A90 Al-Li Alloy Sheet at Elevated Temperature

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.66-68.70 ◽

2011 ◽

Vol 66-68 ◽

pp. 70-75 ◽

Cited By ~ 1

Author(s):

Gao Shan Ma ◽

Song Yang Zhang ◽

Han Ying Wang ◽

Min Wan

Keyword(s):

Flow Stress ◽

Strain Rate ◽

Deformation Behavior ◽

Tensile Deformation ◽

Alloy Sheet ◽

Hot Forming ◽

Uniaxial Tensile ◽

Sensitivity Index ◽

Tensile Deformation Behavior ◽

Increasing Temperature

Uniaxial tensile deformation behavior of 5A90 aluminium-lithium alloy sheet is investigated in the hot forming with the temperature range of 200-450°C and strain rate range of 0.3×10-3-0.2×10-1s-1. It is found that the flow stress of 5A90 Al-Li alloy in uniaxial tension increase with increasing strain rate and decrease with increasing temperature, however, the tendency of total elongation is just the reverse, and the optimum forming temperature is 400°C. The strain rate sensitivity index (m-value) remarkably increases with increasing temperature for a given strain rate. It is shown that 5A90 Al-Li alloy sheet displays the sensitivity to the strain rate at elevated temperatures. For a given strain rate, the strain hardening index (n-value) decreases with increasing temperature, whereas the n-value increases above 350°C. The constitutive equation of stress, strain and strain rate for 5A90 Al-Li alloy at any temperature is obtained by fitting the experimental data, which gave a good flow stress model for the FEM simulation of hot forming.

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Hot tensile deformation behavior and microstructure evolution of Mg-1Al-6Y alloy

Materials Research Express ◽

10.1088/2053-1591/ac34b6 ◽

2021 ◽

Author(s):

Shuai Yuan ◽

Jinhui Wang ◽

Peipeng Jin ◽

Lei Zhang

Keyword(s):

Dynamic Recrystallization ◽

Strain Rate ◽

Deformation Behavior ◽

Basal Slip ◽

Tensile Deformation ◽

Fiber Texture ◽

Effect Of Temperature ◽

Tensile Deformation Behavior ◽

Different Temperatures ◽

Hot Tensile Deformation

Abstract In this study, the hot tensile test was carried out using the extruded and annealed Mg-1Al-6Y alloy. The effect of temperature and strain rate on the hot tensile deformation behavior of the alloy was systematically studied at different temperatures (200 ℃ ~ 350 ℃) and different strain rates (8×10-5 s-1 ~ 1.6×10-3 s-1). In addition, the effect of temperature on the evolution of microstructure when the strain rate is 1.6×10-3 s-1 was investigated. The results showed that as the temperature increased or the strain rate decreased, the peak stress decreased and the elongation increased. Hot tensile at different temperatures all increased the texture intensity, and the microstructure after deformation showed obvious characteristics of basal fiber texture ([0001]⊥ED). Correspondingly, the weaker [-15-40]//ED texture before deformation transformed into a stronger [01-10]//ED fiber texture. After deformation, the average Schmid factor (SF) of each non-basal slip was significantly increased compared with the average SF before deformation, indicating that abundant non-basal slip was activated during the deformation. When the deformation temperature was 300 °C, dynamic recrystallization (DRX) occurred significantly, and the DRXed grains accounted for 15.9%. DRX was a combination of continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX). Furthermore, the calculated activation energy of the alloy was about 98.8 kJ/mol. Comprehensive research showed that the hot tensile deformation mechanism mainly included intragranular slip, grain boundary slip (GBS) and DRX.

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Research on Deformation Behavior of 2024 H18 Aluminum Alloy at Elevated Temperature

Materials Science Forum ◽

10.4028/www.scientific.net/msf.770.329 ◽

2013 ◽

Vol 770 ◽

pp. 329-334 ◽

Cited By ~ 1

Author(s):

Guo Liang Chen ◽

Ning Wang ◽

Ming He Chen

Keyword(s):

Aluminum Alloy ◽

Elevated Temperature ◽

Constitutive Model ◽

Strain Rate ◽

Deformation Behavior ◽

Tensile Deformation ◽

Tensile Elongation ◽

Linear Regression Analysis ◽

Hot Forming ◽

Uniaxial Tensile

Uniaxial tensile deformation behavior of 2024 H18 aluminum sheet alloys was studied in the hot forming process with synchronous cooling temperature range of 300°C~475°C and in the strain rate range of 0.0005/s~0.1/s. The effects of temperature and strain rate on stress, elongation to facture were analyzed. And a constitutive model was proposed to describe the relationship of true stress-true stain by multiple linear regression analysis. It was found that the forming temperature and strain rate have great effect on the hot forming behavior of the alloys. The max stress reduced greatly with the increasing of temperature or reducing of strain rate, while the tensile elongation tended to rise first and then fall with the increasing of temperature and strain rate. The forming of 2024 H18 aluminum alloy at elevated temperature occurred with the strain hardening and dynamic softening. The constitutive model of 2024 H18 aluminum alloy agrees well with the experimental data.

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Study on Constitutive Modeling for Large Deformation Behavior of Polyethylene Considering Strain Rate Effect

Volume 6B: Materials and Fabrication ◽

10.1115/pvp2013-97778 ◽

2013 ◽

Cited By ~ 1

Author(s):

Sijia Zhong ◽

Jianfeng Shi ◽

Jinyang Zheng

Keyword(s):

Strain Rate ◽

Large Deformation ◽

Constitutive Modeling ◽

Deformation Behavior ◽

True Strain ◽

True Stress ◽

Uniaxial Tensile ◽

Pipeline System ◽

Composite Effect ◽

Time Deformation

Polyethylene (PE) pipes have been applied in transportation of key energy medium such as natural gas in the past decades. The mechanical property of PE is of great importance for better design and safer application of PE pipeline system. The large deformation behavior is a key character of PE, not only for its significant strain rate sensitivity, but also for localized necking process after yielding. In this paper, a new constitutive modeling method was proposed to charaterize the rate-denpendent large deformation behavior of PE, in which the true stress is regarded as a function of true stain and true strain rate alone. Uniaxial tensile tests of PE were conducted under various cross-head speeds, and a digital camera was used to record the real-time deformation of specimens. By separating the composite effect into respective effect of local true strain and strain rate on the local true stress in the necking region, a phenomenological model for describing the rate-dependent deformation behavior under uniaxial tension was ealstablished. Model results were validated and found in good agreement with experimental data.

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Comparison in Deformation Behavior, Microstructure, and Failure Mechanism of Nickel Base Alloy 625 under Two Strain Rates

Materials ◽

10.3390/ma14102652 ◽

2021 ◽

Vol 14 (10) ◽

pp. 2652

Author(s):

Meng Liu ◽

Quanyi Wang ◽

Yifan Cai ◽

Dong Lu ◽

Tianjian Wang ◽

...

Keyword(s):

Strain Rate ◽

Deformation Behavior ◽

Tensile Deformation ◽

Base Alloy ◽

Inconel 625 ◽

Tensile Fracture ◽

Nickel Base Superalloy ◽

Strain Rates ◽

Tensile Fracture Surface ◽

Nickel Base

Tensile deformation behavior and microstructure of nickel-base superalloy Inconel 625 are investigated under different strain rates of 5 × 10−4 s−1 and 5 × 10−5 s−1. According to the experimental results, yield strength and ultimate tensile strength of the alloy increase with the increase in strain rate in room temperature. Microstructure results indicate that the size of dimples is smaller in the tensile fracture surface at low strain rate than the high strain rate, and the number of dimples is also related to the strain rates and twins appear earlier in the specimens with higher strain rates. Apart from Hollomon and Ludwik functions, a new formula considering the variation trend of strength in different deformation stages is deduced and introduced, which fit closer to the tensile curves of the 625 alloy used in the present work at both strain rates. Furthermore, the Schmid factors of tensile samples under two strain rates are calculated and discussed. In the end, typical work hardening behavior resulting from the dislocations slip behavior under different strain rates is observed, and a shearing phenomenon of slip lines cross through the δ precipitates due to the movement of dislocations is also be note.

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The effect of strain rates on tensile deformation of ultrafine-grained copper

International Journal of Modern Physics B ◽

10.1142/s0217979217440143 ◽

2017 ◽

Vol 31 (16-19) ◽

pp. 1744014

Author(s):

M. Li ◽

Q. W. Jiang

Keyword(s):

Strain Rate ◽

Deformation Behavior ◽

Room Temperature ◽

Tensile Deformation ◽

Strain Rates ◽

Roll Bonding ◽

Fracture Elongation ◽

Tensile Deformation Behavior ◽

Ultrafine Grained ◽

Flow Stress Level

Tensile deformation behavior of ultrafine-grained (UFG) copper processed by accumulative roll-bonding (ARB) was studied under different strain rates at room temperature. It was found that the UFG copper under the strain rate of 10[Formula: see text] s[Formula: see text] led to a higher strength (higher flow stress level), flow stability (higher stress hardening rate) and fracture elongation. In the fracture surface of the sample appeared a large number of cleavage steps under the strain rate of 10[Formula: see text] s[Formula: see text], indicating a typical brittle fracture mode. When the strain rate is 10[Formula: see text] or 10[Formula: see text] s[Formula: see text], a great amount of dimples with few cleavage steps were observed, showing a transition from brittle to plastic deformation with increasing strain rate.

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A Flow Stress Model of 300M Steel for Isothermal Tension

Materials ◽

10.3390/ma14020252 ◽

2021 ◽

Vol 14 (2) ◽

pp. 252

Author(s):

Rongchuang Chen ◽

Shiyang Zhang ◽

Xianlong Liu ◽

Fei Feng

Keyword(s):

Flow Stress ◽

Constitutive Model ◽

Tensile Deformation ◽

Flow Behavior ◽

Tensile Tests ◽

Uniaxial Tensile ◽

Model Parameters ◽

Average Deviation ◽

Cross Sectional ◽

300M Steel

To investigate the effect of hot working parameters on the flow behavior of 300M steel under tension, hot uniaxial tensile tests were implemented under different temperatures (950 °C, 1000 °C, 1050 °C, 1100 °C, 1150 °C) and strain rates (0.01 s−1, 0.1 s−1, 1 s−1, 10 s−1). Compared with uniaxial compression, the tensile flow stress was 29.1% higher because dynamic recrystallization softening was less sufficient in the tensile stress state. The ultimate elongation of 300M steel increased with the decrease of temperature and the increase of strain rate. To eliminate the influence of sample necking on stress-strain relationship, both the stress and the strain were calibrated using the cross-sectional area of the neck zone. A constitutive model for tensile deformation was established based on the modified Arrhenius model, in which the model parameters (n, α, Q, ln(A)) were described as a function of strain. The average deviation was 6.81 MPa (6.23%), showing good accuracy of the constitutive model.

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High Temperature Deformation Mechanism Maps of NiAl

Materials Science Forum ◽

10.4028/www.scientific.net/msf.449-452.57 ◽

2004 ◽

Vol 449-452 ◽

pp. 57-60

Author(s):

I.G. Lee ◽

A.K. Ghosh

Keyword(s):

High Temperature ◽

Strain Rate ◽

Deformation Mechanism ◽

Calculation Method ◽

Deformation Behavior ◽

Tensile Tests ◽

High Temperature Deformation ◽

Temperature Deformation ◽

Grain Sizes ◽

Temperature Strain

In order to analyze high temperature deformation behavior of NiAl alloys, deformation maps were constructed for stoichiometric NiAl materials with grain sizes of 4 and 200 µm. Relevant constitute equations and calculation method will be described in this paper. These maps are particularly useful in identifying the location of testing domains, such as creep and tensile tests, in relation to the stress-temperature-strain rate domains experienced by NiAl.

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Experimental investigations of the human oesophagus: anisotropic properties of the muscular layer in large deformation

10.1101/2021.07.18.452813 ◽

2021 ◽

Author(s):

Ciara Durcan ◽

Mokarram Hossain ◽

Gregory Chagnon ◽

Djordje Peric ◽

Lara Bsiesy ◽

...

Keyword(s):

Strain Rate ◽

Ex Vivo ◽

Longitudinal Direction ◽

Tensile Tests ◽

Endoscopic Biopsy ◽

Circumferential Direction ◽

Experimental Investigations ◽

Uniaxial Tensile ◽

Rate Dependency ◽

Muscular Layer

Technological advancements in the field of robotics have led to endoscopic biopsy devices able to extract diseased tissue from between the layers of the gastrointestinal tract. Despite this, the layer-dependent properties of these tissues have yet to be mechanically characterised using human tissue. In this study, the ex vivo mechanical properties of the passive muscularis propia layer of the human oesophagus were extensively investigated. For this, a series of uniaxial tensile tests were conducted. The results displayed hyperelastic behaviour, while the differences between loading the tissue in both the longitudinal and circumferential directions showcased its anisotropy. The anisotropy of the muscular layer was present at different strain rates, with the longitudinal direction being consistently stiffer than the circumferential one. The circumferential direction was found to have little strain-rate dependency, while the longitudinal direction results suggest pronounced strain-rate-dependent behaviour. The repeated trials showed larger variation in terms of stress for a given strain in the longitudinal direction compared to the circumferential direction. The possible causes of variation between trials are discussed, and the experimental findings are linked to the histological analysis which was carried out via various staining methods. Finally, the direction-dependent experimental data was simulated using an anisotropic, hyperelastic model.

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