Hot Compressive Behavior and Constitutive Equation of Ti-Al-Nb-Zr-Mo-Cr Alloy

2020 ◽  
Vol 993 ◽  
pp. 230-236
Author(s):  
Li Wei Zhu ◽  
Yun Peng Xin ◽  
Xin Nan Wang ◽  
Zhi Shou Zhu
Keyword(s):  
Activation Energy ◽  
Titanium Alloy ◽  
Flow Stress ◽  
Constitutive Equation ◽  
Deformation Behavior ◽  
Flow Behavior ◽  
True Stress ◽  
Compressive Behavior ◽  
Hot Deformation Behavior ◽  
Peak Value

The hot deformation behavior of Ti-Al-Nb-Zr-Mo-Cr titanium alloy was studied by hot compressive method in this paper, and the flow stress constitutive equation and activation energy also calculated. The results show that the flow stress increased with deformation temperature dropping and strain rate increasing. The flow behavior of the sample hot-deformaed exhibited a peak value of stress in the α+β field, whereas, the true stress attained a steady state in the β field. According to the stress-strain curves of the alloy and its stress characteristics, the Arrhenius constitutive equation was obtained. The average activation energy was about 654.228 KJ/mol in the α+β field, and about 272.196 KJ/mol in the β field, respectively.

Hot Deformation Behavior and Constitutive Equation of Mg-4Al-3Ca -1.5Zn-1Nd-0.2Mn Magnesium Alloy As-Extruded

2014 ◽  
Vol 900 ◽  
pp. 588-591
Author(s):  
Gang Chen ◽  
Wei Chen ◽  
Guo Wei Zhang ◽  
Jing Zhai ◽  
Li Ma ◽  
...  
Keyword(s):  
Activation Energy ◽  
Flow Stress ◽  
Magnesium Alloy ◽  
Constitutive Equation ◽  
Constitutive Equations ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Strain Rates ◽  
Compression Tests ◽  
Hot Deformation Behavior

The deformation behavior and constitutive equation of Mg-4Al-3Ca-1.5Zn-1Nd-0.2Mn alloy were investigated using hot compression tests at the temperatures range of 200, 250, 300, and 350°C with the constant strain rates of 0.001, 0.01, 0.1 And1 s-1. The influence of strain was also incorporated in the constitutive equation by considering the effects of strain on material constants which are consist of A, α, β, n and activation energy Q. The predicted flow stress curves using the proposed constitutive equations well agree with the experimental results of the flow stress for experimental Alloy.

scholarly journals Hot Deformation Behavior and Hot Rolling Properties of a Nano-Y2O3 Addition Near-α Titanium Alloy

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 837
Author(s):  
Zhuangzhuang Zheng ◽  
Yuyong Chen ◽  
Fantao Kong ◽  
Xiaopeng Wang ◽  
Yucheng Yu
Keyword(s):  
Activation Energy ◽  
Titanium Alloy ◽  
Hot Rolling ◽  
Deformation Behavior ◽  
Processing Map ◽  
Dynamic Recovery ◽  
Alloy Sheet ◽  
Hot Deformation Behavior ◽  
Hot Processing Map ◽  
Y2o3 Addition

The hot deformation behavior and hot rolling based on the hot processing map of a nano-Y2O3 addition near-α titanium alloy were investigated. The isothermal compression tests were conducted at various deformation temperatures (950⁠–1070 °C) and strain rates (0.001–1 s−1), up to a true strain of 1.2. The flow stress was strongly dependent on deformation temperature and strain rate, decreasing with increased temperature and decreased strain rate. The average activation energy was 657.8 kJ/mol and 405.9 kJ/mol in (α + β) and β region, respectively. The high activation energy and peak stress were contributed to the Y2O3 particles and refractory elements comparing with other alloys and composites. The deformation mechanisms in the (α + β) region were dynamic recovery and spheroidization of α phase, while the β phase field was mainly controlled by the dynamic recrystallization and dynamic recovery of β grains. Moreover, the constitutive equation based on Norton–Hoff equation and hot processing map were also obtained. Through the optimal processing window determined by the hot processing map at true strains of 0.2, 0.4 and 0.6, the alloy sheet with multi-pass hot rolling (1050 °C/0.03–1 s−1) was received directly from the as-cast alloy. The ultimate tensile strength and yield strength of the alloy sheet were 1168 MPa and 1091 MPa at room temperature, and 642 MPa and 535 MPa at 650 °C, respectively, which performs some advantages in current research.

scholarly journals Hot deformation behavior of TC18 titanium alloy

2013 ◽  
Vol 17 (5) ◽  
pp. 1523-1528
Author(s):  
Bao-Hua Jia ◽  
Wei-Dong Song ◽  
Hui-Ping Tang ◽  
Jian-Guo Ning
Keyword(s):  
Titanium Alloy ◽  
Flow Stress ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
True Strain ◽  
Testing Machine ◽  
Constitutive Relationship ◽  
Compression Tests ◽  
Hot Deformation Behavior

Isothermal compression tests of TC18 titanium alloy at the deformation temperatures ranging from 25?C to 800?C and strain rate ranging from 10-4 to 10-2 s-1 were conducted by using a WDW-300 electronic universal testing machine. The hot deformation behavior of TC18 was characterized based on an analysis of the true stress-true strain curves of TC18 titanium alloy. The curves show that the flow stress increases with increasing the strain rate and decreases with increasing the temperature, and the strain rate play an important role in the flow stress when increasing the temperatures. By taking the effect of strain into account, an improved constitutive relationship was proposed based on the Arrhenius equation. By comparison with the experimental results, the model prediction agreed well with the experimental data, which demonstrated the established constitutive relationship was reliable and can be used to predict the hot deformation behavior of TC18 titanium alloy.

The Hot Deformation Behavior and Microstructural Evolution of Ti-6Al-2Zr-3Ni Alloy

2012 ◽  
Vol 452-453 ◽  
pp. 61-65
Author(s):  
Xuan Xiao ◽  
Hui Xu ◽  
Li Yuan Sheng ◽  
Lan Zhang Zhou
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Microstructural Evolution ◽  
Temperature Sensitivity ◽  
Deformation Behavior ◽  
Dynamic Recovery ◽  
Constant Strain Rate ◽  
True Stress ◽  
Hot Deformation Behavior ◽  
Lower Temperature

Hot compression deformation behavior of Ti-6Al-2Zr-3Ni alloy was investigated through thermal simulation tests in the range of 900- 1050°C, with strain rate from 0.001 s-1 to 1 s-1. The results demonstrates that flow stress reaches the maximum quickily, followed by flow softening with the increase of strain in all true stress-strain curves. At a constant strain rate, flow stress will decrease with the test temperature. Moreover, the temperature sensitivity of flow stress reduces largely at temperature between 980 to 1050°C, during which dynamic recovery is the main mechanism for the hot deformed alloy. In addition, flow stress increases with the strain rate. At lower temperature, recrystallization reduces or vanishes at temperature ranging from 900 to 940 °C due to thermodynamics factors.

scholarly journals Constitutive Model Prediction and Flow Behavior Considering Strain Response in the Thermal Processing for the TA15 Titanium Alloy

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1985 ◽  
Author(s):  
Jiang Li ◽  
Fuguo Li ◽  
Jun Cai
Keyword(s):  
Titanium Alloy ◽  
Flow Stress ◽  
Constitutive Equation ◽  
Flow Behavior ◽  
Strain Effect ◽  
Absolute Relative Error ◽  
Average Absolute Relative Error ◽  
Ta15 Titanium Alloy ◽  
Measured Stress ◽  
The Impact

To investigate the flow stress, microstructure, and usability of TA15 titanium alloy, isothermal compression was tested at 1073–1223 K and strain rates of 10, 1, 0.1, 0.01, and 0.001 s−1, and strain of 0.9. The impact of strain and temperature on thermal deformation was investigated through the exponent-type Zener–Hollomon equation. Based on the influence of various material constants (including α, n, Q, and lnA) on the TA15 titanium alloy, the strain effect was included in the constitutive equation considering strain compensation, which is presented in this paper. The validity of the proposed constitutive equation was verified through the correlation coefficient (R) and the average absolute relative error (AARE), the values of which were 0.9929% and 6.85%, respectively. Research results demonstrated that the strain-based constitutive equation realizes consistency between the calculated flow stress and the measured stress of TA15 titanium alloy at high temperatures.

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.

scholarly journals Hot Deformation Behavior and Strain-Compensated Constitutive Equation of Nano-Sized SiC Particle-Reinforced Al-Si Matrix Composites

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1812 ◽  
Author(s):  
Zhen Wang ◽  
Aiqin Wang ◽  
Jingpei Xie ◽  
Pei Liu
Keyword(s):  
Activation Energy ◽  
Constitutive Equation ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Pure Aluminum ◽  
Matrix Composites ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Arrhenius Function ◽  
Sic Particle

The hot deformation behavior of nano-SiCp/Al-Si composites was studied by isothermal compression tests at 470–530 °C and strain rates of 0.01–5 s−1. A strain-compensation constitutive model was developed with a Z parameter and an Arrhenius function, and its accuracy was verified by error analysis. The results show that the flow stress of the composites decreased with the increase in deformation temperature and the decrease in strain rate. The average activation energy for nano-SiC particle-reinforced Al-Si matrix composites was 277 kJ/mol, which was larger than the activation energy for self-diffusion of pure aluminum. The average relative error was calculated as 2.88%, indicating the strain-compensated constitutive equation could accurately predict the hot deformation behavior of nano-SiCp/Al-Si composites.

Characterization of Hot Deformation Behavior of Ti-4.5Al-3V-2Mo-2Fe Titanium Alloy

2016 ◽  
Vol 849 ◽  
pp. 309-316 ◽  
Author(s):  
Li Wei Zhu ◽  
Xin Nan Wang ◽  
Yue Fei ◽  
Jing Li ◽  
Zhi Shou Zhu
Keyword(s):  
Titanium Alloy ◽  
Flow Stress ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Constant Strain Rate ◽  
Test Machine ◽  
Peak Efficiency ◽  
Hot Deformation Behavior ◽  
Dynamic Materials

The hot deformation behavior of Ti-4.5Al-3V-2Mo-2Fe (SP-700) titanium alloy in the temperature range of 650°C~950°C and constant strain rate of 0.01, 0.1, 1 and 10s-1 has been investigated by hot compressive testing on the Gleeble-1500D thermal simulation test machine. The experimental results indicated that the hot deformation behavior of SP-700 alloy was sensitive to the deformation temperature and strain rate. The peak flow stress decreased with the increase of temperature and the decrease of strain rate. The flow curves characteristic under different deformation parameters show significant different. Analysis of the flow stress dependence on strain rate and temperature gives a stress exponent of n as 4.8235 and a deformation activation energy of Q as 410kJ/mol. Based on the dynamic materials model, the processing map is generated, which shows that the most peak efficiency domain appears at the temperature of 725°C~775°C and the strain rate of 0.001 s-1~0.003s-1 with a peak efficiency of 45% at about 750°C/0.01s-1.

scholarly journals On the Capability of Logarithmic-Power Model for Prediction of Hot Deformation Behavior of Alloy 800H at High Strain Rates

2019 ◽  
Vol 38 (2019) ◽  
pp. 84-91 ◽  
Author(s):  
E. Shafiei ◽  
A. Soltani Tehrani
Keyword(s):  
Flow Stress ◽  
Constitutive Equation ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
High Strain ◽  
Power Model ◽  
Strain Rates ◽  
Hot Deformation Behavior ◽  
High Strain Rates ◽  
Alloy 800H

AbstractIn this study, the logarithmic-power model has been used to predict hot deformation behavior of alloy 800H at high temperatures. This is for the first time that the logarithmic-power model is examined to model the flow stress curves with negligible flow softening at high strain rates. To this end, flow stress curves of alloy 800H obtained at deformation temperatures from 850°C to 1050°C and at strain rates of 5 and 10 S−1 were employed. The Johnson–Cook model and Shafiei constitutive equation were also used to prove the accuracy of the logarithmic-power model in prediction of flow stress curves of alloy 800H. Evaluation of mean error of flow stress at different deformation conditions showed that the logarithmic-power model can give a more precise estimation of flow stress curves than Johnson–Cook model. Furthermore, it was found out that the accuracy of the Logarithmic-power model and Shafiei constitutive equation was roughly the same in terms of maximum errors obtained in prediction of flow stress curves. Accordingly, it can be concluded that the logarithmic-power model can be employed as a comprehensive model for a wide range of deformation conditions.

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