Study on Constitutive Equation of 7085 Aluminum Alloy under High Deformation Temperature

2015 ◽  
Vol 1095 ◽  
pp. 579-582
Author(s):  
Rui Bin Mei ◽  
Bo Zhang ◽  
B. Cai ◽  
X.Y. Zhang ◽  
Z.T. Zou ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Flow Stress ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Deformation Temperature ◽  
Peak Stress ◽  
Strain Rate Range ◽  
Peak Strain ◽  
Stress Strain ◽  
Deformation Velocity

The flow stress behavior of the 7085 aluminum alloy was studied through single-pass compression experiment by using MMS-300 simulator within temperature range of 300-450°C and strain rate range of 0.01-10s-1. Dynamic recrystallization occurs in hot compression of 7085 alloy and the stress-strain curves are presented as wave with higher deformation temperature and strain rate. Increasing of deformation velocity and reducing temperature results in higher peak stress. Then a mathematical model has been developed to predict the stress-strain curves based on phenomenological representation of the curves and the traditional theories for constitutive equations which incorporate the power law. The constitutive equation expressed in terms of peak stress, peak strain and additional parameters to predict flow stress. The stress-strain curves of 7085 alloy predicted by this model are in good agreement with experimental results.

The Flow Stress Feature and Constitutive Equation of 6016 Aluminum Alloy during Hot Compression

2012 ◽  
Vol 538-541 ◽  
pp. 1687-1692
Author(s):  
Ji Xiang Zhang ◽  
Wei Feng ◽  
Hui Wen ◽  
Guo Yin An
Keyword(s):  
Aluminum Alloy ◽  
Flow Stress ◽  
Linear Regression ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Strain Rate Range ◽  
Thermal Simulation ◽  
Hot Compression ◽  
Rate Range ◽  
6016 Aluminum Alloy

The flow stress behavior of 6016 aluminum alloy was investigated on the condition of temperature range from 420°C to 540°C and strain rate range from 0.001s-1to 1s-1based on hot compression experiment on Gleeble-1500 thermal simulation machine. The result shows that the flow stress of 6016 aluminum alloy decreases with the enhancement of temperature and increases with the increase of strain rate. Especially, the flow stress increases tendency becomes obvious when the strain rate greater than 0.1s-1. Based on the results above, a constitutive equation for flow stress of 6016 aluminum alloy when the temperature is above 420°C is obtained by linear regression.

Research on Compressive Behavior and Deformation Heating of 7075-T6 Aluminum Alloy during Hot Compression

2014 ◽  
Vol 887-888 ◽  
pp. 315-318
Author(s):  
Dong Ge Wang ◽  
Rui Bin Mei ◽  
Ban Cai ◽  
Chun Li Zhang ◽  
Li Bao ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Flow Stress ◽  
Strain Rate ◽  
Temperature Rise ◽  
Strain Rate Range ◽  
Hot Compression ◽  
Deformation Heating ◽  
Deformation Velocity ◽  
Fluctuation Range ◽  
The Relationship

The flow stress behavior of the 7075-T6 aluminum alloy was studied through single-pass compression experiment by using MMS-300 simulator within temperature range of 300-450°C and strain rate range of 0.01-40s-1. Then a simulation of compression was carried out and the influence of deformation velocity on load and deformation heating was investigated according to the relationship between stress and strain. The results show that dynamic recrystallization occurs in hot compression of 7075-T6 alloy and the stress-strain curves are presented as wave. Furthermore, the flow stress curves have the same wave period and the fluctuation range increases with an increase of strain rate and a decrease of strain. Increasing of deformation velocity results in higher critical strain but the value decreases when the deformation velocity is much higher. The temperature rise increases with the increase of deformation velocity and decrease of deformation temperature. The maximum of temperature rise is more than about 30°C, so that the deformation heating is significant.

Constitutive Equation of 5Cr21Mn9Ni4N Valve Steel during Hot Compression

2013 ◽  
Vol 750-752 ◽  
pp. 2165-2169 ◽  
Author(s):  
Yong Qi Cheng ◽  
Zheng Rong Zhang ◽  
Miao Yan Zheng ◽  
Dong Qiang Mo
Keyword(s):  
Flow Stress ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Constitutive Equations ◽  
Peak Stress ◽  
Strain Rate Range ◽  
Hot Compression ◽  
Compression Tests ◽  
State Regime ◽  
Valve Steel

The hot compression tests on a Gleeble-1500D thermal mechanics simulator were carried out under the strain rate range of 1~ 0.005s-1 at the temperature range of 873-1373K in order to evaluate the constitutive equation of 5Cr21Mn9Ni4N valve steel. All of the flow stress curves exhibit a single peak stress, after which the stress is followed by a steady state regime. The results indicate that the deforming behavior is strongly depending on the strain rate and the deforming temperature. According the experimental data, the hyperbolic law is used to develop the constitutive equations. In the constitutive equations, the effect of the deforming temperature and the strain rate are represented by the Zener-Hollomam parameter. And the flow stress curves are coinciding with the constitutive equation of .

The Flow Stress Characteristic and Constitutive Equation of 6016 Aluminum Alloy in Warm Forming

2011 ◽  
Vol 228-229 ◽  
pp. 1112-1117 ◽  
Author(s):  
Ji Xiang Zhang ◽  
Hui Wen ◽  
Wei Feng ◽  
Guo Yin An ◽  
Jin Xi Liu
Keyword(s):  
Aluminum Alloy ◽  
Flow Stress ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Deformation Temperature ◽  
Linear Regression Analysis ◽  
Alloy Sheet ◽  
Warm Forming ◽  
Aluminum Alloy Sheet ◽  
6016 Aluminum Alloy

In order to realize numerical simulation of warm forming and reasonably establish the warm formation process parameters for 6016 aluminum alloy, we study the forging process of 6016 aluminum alloy with warm compression experiments on the Gleele-1500 thermal simulation testing machine, and research the deformation flow stress behavior of the aluminum alloy sheet at different temperatures , strain rate under the warm forming. The results show that the deformation temperature and strain rate have significant influence on flow stress of 6016 aluminum alloy sheet, that is, the alloy is a temperature and strain rate sensitive materials, and the flow stress increases with the increase of strain rate and decreases with the increase of deformation temperature. The deformation constitutive equation of 6016 aluminum alloy is got by multiple linear regression analysis. The constitutive equation is consistent with the experimental curves rather well, which confirms the accuracy of the constitutive equation.

A Modified Double Multiple Nonlinear Regression Constitutive Equation for Modeling and Prediction of High Temperature Flow Behavior of BFe10-1-2 Alloy

2018 ◽  
Vol 37 (1) ◽  
pp. 75-87
Author(s):  
Jun Cai ◽  
Kuaishe Wang ◽  
Jiamin Shi ◽  
Wen Wang ◽  
Yingying Liu
Keyword(s):  
Flow Stress ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Nonlinear Regression ◽  
Flow Behavior ◽  
Strain Rate Range ◽  
Compression Tests ◽  
Constitutive Analysis ◽  
Average Absolute Relative Error ◽  
Wide Range

AbstractConstitutive analysis for hot working of BFe10-1-2 alloy was carried out by using experimental stress–strain data from isothermal hot compression tests, in a wide range of temperature of 1,023~1,273 K, and strain rate range of 0.001~10 s–1. A constitutive equation based on modified double multiple nonlinear regression was proposed considering the independent effects of strain, strain rate, temperature and their interrelation. The predicted flow stress data calculated from the developed equation was compared with the experimental data. Correlation coefficient (R), average absolute relative error (AARE) and relative errors were introduced to verify the validity of the developed constitutive equation. Subsequently, a comparative study was made on the capability of strain-compensated Arrhenius-type constitutive model. The results showed that the developed constitutive equation based on modified double multiple nonlinear regression could predict flow stress of BFe10-1-2 alloy with good correlation and generalization.

Hot Deformation Behavior and Microstructure Evolution of a DC Cast Hypereutectic Al-Si Alloy

2012 ◽  
Vol 151 ◽  
pp. 332-336
Author(s):  
Ke Zhun He ◽  
Fu Xiao Yu ◽  
Da Zhi Zhao ◽  
Liang Zuo
Keyword(s):  
Strain Rate ◽  
Microstructure Evolution ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Peak Stress ◽  
Strain Rate Range ◽  
Hot Deformation Behavior ◽  
Strong Function ◽  
Primary Si

The hot deformation behavior and microstructure evolution of a DC cast hypereutectic Al-Si alloy was studied in the temperature range of 400-500 °C and strain rate range of 0.001-1 s-1. The results show that the as-cast microstructure of the alloy consists of polygonal primary Si particles and α-aluminum dendritic halos with Al-Si eutectics and intermetallic compounds segregated into the interdendritic regions. The flow stress of the alloy is a strong function of temperature and strain rate, and the peak stress is increased with the decrease of deformation temperature and the increase of strain rate. All the true stress-true stain curves in the experiments exhibit dynamic softening. The fracture frequency of primary Si particle is decreased with the increase of deformation temperature and the decrease of strain rate. The dynamic flow softening is mainly as a result of dynamic recrystallization.

Effect of Efficient Purification on Mechanical Properties of 3003 Aluminum Alloy

2018 ◽  
Vol 777 ◽  
pp. 402-407
Author(s):  
Gui Qing Chen ◽  
Gao Sheng Fu ◽  
Xiao Dong Lin ◽  
Jun De Wang ◽  
Chao Zeng Cheng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Flow Stress ◽  
Aluminum Alloys ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Deformation Temperature ◽  
Room Temperature ◽  
Inclusion Size ◽  
Isothermal Compression

3003 aluminum melt was treated with efficient purification, and it was deformed by isothermal compression in the range of deformation temperature 300-500 °C at strain rate 0.0l-10.0 s-1 with Gleeble-1500 thermal simulator. The results show that efficient purification treatment can significantly reduce the impurities, and make inclusion size smaller, uniform distribution. Room temperature mechanical properties were significantly improved. At the same strain rate, the flow stress of 3003 aluminum alloy decreases with the increase of deformation temperature. The flow stress increases with the increase of strain rate under the same deformation temperature. Two kinds of 3003 aluminum alloys with different purification treatments both have dynamic recrystallization characteristics. Especially when the strain rate reaches 10.0 s-1, the rheological curve appears sawtooth fluctuation and the alloy may have discontinuous dynamic recrystallization.

scholarly journals An Improved Johnson–Cook Constitutive Model and Its Experiment Validation on Cutting Force of ADC12 Aluminum Alloy During High-Speed Milling

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1038
Author(s):  
Xinxin Meng ◽  
Youxi Lin ◽  
Shaowei Mi
Keyword(s):  
Aluminum Alloy ◽  
Flow Stress ◽  
Constitutive Equation ◽  
Constitutive Model ◽  
Strain Rate ◽  
Cutting Force ◽  
High Speed ◽  
Cutting Speed ◽  
Experimental Results ◽  
Element Analysis

Because of the massive work and high cost of milling experiments, finite element analysis technology (FEA) was used to analyze the milling process of ADC12 aluminum alloy. An improved Johnson–Cook (J–C) constitutive equation was fitted by a series of dynamic impact tests in different strain rates and temperatures. It found that the flow stress gradually increases as the strain rate rises, but it decreases as the test temperature rises. Compared with the J–C constitutive model, the predicted flow stress by the improved J–C constitutive model was closer to the experimental results when the strain rate was larger than 8000 s−1 and the temperature was higher than 300 °C. A two-dimensional cycloidal cutting simulation model was constructed based on the two J–C constitutive equations which was validated by milling experiments at different cutting speeds. The simulation results based on the improved J–C constitutive equation were closer to the experimental results and showed the cutting force first increased and then decreased, with cutting speed increasing, reaching a maximum at 600 m/min.

Establishment of Flow Stress Model of EW75 Alloy

2013 ◽  
Vol 423-426 ◽  
pp. 241-246
Author(s):  
Ming Long Ma ◽  
Kui Zhang
Keyword(s):  
Mathematical Model ◽  
Flow Stress ◽  
Magnesium Alloy ◽  
Strain Rate ◽  
Strain Rate Range ◽  
Strain Rates ◽  
Stress Strain ◽  
Deformation Degree ◽  
Maximum Deformation ◽  
The Mathematical Model

The behavior evolvement of Mg-7.22Gd-4.84Y-1.26Nd-0.58Zr (EW75) magnesium alloy during the hot deformation process was discussed. The flow stress behavior of magnesium alloy over the strain rate range 0.002s-1to 2s-1and the temperature range 623K to 773K had been researched on Gleeble-1500D hot simulator under the maximum deformation degree 60%. A mathematical model was established to predict the stress-strain curves of this alloy during deformation. The experimental results showed that the stress-strain curves were obviously affected by the strain rates and deformation temperatures. The mathematical model could predict the stress-strain curves when the strain rates were under 0.2-1, but there was significant error in some of stress-strain curves when the strain-rate was 2-1by the reason of deformation temperature rising.

scholarly journals Hot Deformation Behavior and Constitutive Modeling of H13-Mod Steel

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 846 ◽  
Author(s):  
Changmin Li ◽  
Yuan Liu ◽  
Yuanbiao Tan ◽  
Fei Zhao
Keyword(s):  
Constitutive Equation ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
High Strain ◽  
Flow Behavior ◽  
Peak Stress ◽  
Strain Rates ◽  
Hot Deformation Behavior ◽  
Stress Strain

The H13-mod steel optimized by composition and heat treatment has reached the performance index of the shield machine hob. The hot deformation behavior of the H13-mod steel was investigated by compression tests in the temperature range from 900 to 1150 °C and the strain rate range from 0.01 to 10 s−1. The true stress-strain curve showed that the rising stress at the beginning of deformation was mainly caused by work hardening. After the peak stress was attained, the curve drop and the flow softening phenomenon became more obvious at low strain rates. The flow behavior of the H13-mod steel was predicted by a strain-compensated Arrhenius-type constitutive equation. The relationship between the material constant in the Arrhenius-type constitutive equation and the true strain was established by a sixth-order polynomial. The correlation coefficient between the experimental value and the predicted value reached 0.987, which indicated that the constitutive equation can accurately estimate the flow stress during the deformation process. A good linear correlation was achieved between the peak stress (strain), critical stress (strain) and the Zener‒Hollomon parameters. The processing maps of the H13-mod steel under different strains were established. The instability region was mainly concentrated in the high-strain-rate region; however, the microstructure did not show any evidence of instability at high temperatures and high strain rates. Combined with the microstructure and electron backscattered diffraction (EBSD) test results under different deformations, the optimum hot working parameters were concluded to be 998–1026 °C and 0.01–0.02 s−1 and 1140–1150 °C and 0.01–0.057 s−1.

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