scholarly journals Hot Deformation Behavior of a New Al–Mn–Sc Alloy

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 22
Author(s):  
Weiqi Kang ◽  
Yi Yang ◽  
Sheng Cao ◽  
Lei Li ◽  
Shewei Xin ◽  
...  

The hot deformation behavior of a new Al–Mn–Sc alloy was investigated by hot compression conducted at temperatures from 330 to 490 °C and strain rates from 0.01 to 10 s−1. The hot deformation behavior and microstructure of the alloy were significantly affected by the deformation temperatures and strain rates. The peak flow stress decreased with increasing deformation temperatures and decreasing strain rates. According to the hot deformation behavior, the constitutive equation was established to describe the steady flow stress, and a hot processing map at 0.4 strain was obtained based on the dynamic material model and the Prasad instability standard, which can be used to evaluate the hot workability of the alloy. The developed hot processing diagram showed that the instability was more likely to occur in the higher Zener–Hollomon parameter region, and the optimal processing range was determined as 420–475 °C and 0.01–0.022 s−1, in which a stable flow and a higher power dissipation were achieved.

2018 ◽  
Vol 913 ◽  
pp. 30-36
Author(s):  
Ran Liu ◽  
Hui Huang ◽  
Ya Liu ◽  
Li Rong

To study the hot deformation behavior of Al-Mg-Er alloy, hot compression tests were conducted on a Gleeble-1500D thermal simulator at the temperature range of 200-500°C with the strain rates from 0.001 to 10s-1. With the increase in the deformation temperature and the decrease in strain rates, the flow stress of the Al-Mg-Er alloy decreased. Processing maps were constructed to study on hot workability characteristics. The results showed that the flow stress curves exhibited the typical dynamic recrystallization characteristics and the stress decreased with the increase of deformation temperature and the decrease of strain rate. Moreover, the processing maps were established on the basis of dynamic material model and Prasad’s instability criterion.


2014 ◽  
Vol 788 ◽  
pp. 45-51
Author(s):  
Yong Biao Yang ◽  
Zhi Min Zhang ◽  
Feng Li Ren ◽  
Qiang Wang

The elevated temperature flow stress behavior of Mg-9Gd-2.5Y-1Nd-0.5Zr magnesium alloy was carried out by Gleeble-1500 thermal mechanical simulator in the temperature range of 460-520°C and in strain rates of 0.0005~1s-1 at a strain of 0.6. The optical microscopy was used for microstructure characterization. The results showed that the flow stress increases with increasing strain rates and decreasing temperature. All the deformed magnesium alloy specimens show a dynamic recovery characters in the temperature range from 460~500°C, and show dynamic recrystallization characters at 520°C. The flow stress of this alloy can be represented by Zener-Hollomon parameter function, and values of related parameters A, α and n, are 2.24×1013s-1、0.027MPa-1 and 2.93, respectively. Its activation energy for hot deformation Q is 212.6kJ/mol.


2016 ◽  
Vol 684 ◽  
pp. 35-41 ◽  
Author(s):  
S.V. Rushchits ◽  
E.V. Aryshensky ◽  
S.M. Sosedkov ◽  
A.M. Akhmed'yanov

The deformation behavior of 1565ch alloy under the plane-strain conditions in the temperature range of 350–490 оС and strain rates range of 0,1–10 s-1 is studied. The expression for steady flow stress as the functions of temperature of deformation and strain rate is obtained. It is established that 1565ch alloy with zirconium addition shows higher strain resistance and less tendency to dynamic and static recrystallization than AMg6.


2017 ◽  
Vol 36 (5) ◽  
pp. 467-475
Author(s):  
Rui Luo ◽  
Qi Zheng ◽  
Zhending Tang ◽  
Yongquan Yao ◽  
Guifang Xu ◽  
...  

AbstractHigh-temperature single-pass compression experiments were conducted on alloy 800H using a Gleeble 3500 thermal-mechanical simulation testing machine, and hot deformation behaviors at temperatures of 1,000–1,150 °C and strain rates of 0.01–1 s–1 were investigated. The results revealed that dynamic recrystallization (DRX) behavior occurred more easily under deformation conditions with relatively low strain rates and high deformation temperatures. By taking the influence of strain on the hot deformation behavior into consideration, a strain-dependent hyperbolic sine constitutive model was constructed. Based on this revised constitutive model, flow stress during deformation was predicted. The linear relation between the predicted value and the experimental result was as high as 0.99648, and the absolute average relative error was 2.019 %. Thus, it was demonstrated that the strain-dependent analysis provided a constitutive model that was able to precisely predict flow stress under experimental conditions.


2018 ◽  
Vol 941 ◽  
pp. 458-467
Author(s):  
Nima Safara Nosar ◽  
Fredrik Sandberg ◽  
Göran Engberg

The behavior of a 13% chromium steel subjected to hot deformation has been studied by performing hot compression tests in the temperature range of 850 to 12000C and at strain rates from 0.01 to 10 s-1. The uniaxial hot compression tests were performed on a Gleeble thermo-mechanical simulator. The best function that fits the peak stress for the material and its relation to the Zener-Hollomon parameter (Z) is derived. The average activation energy of this alloy in the entire test domain was found to be about 557 [kJmol-1] and the dynamic recrystallization (DRX) kinetics was studied to find the fraction DRX during deformation.


2019 ◽  
Vol 38 (2019) ◽  
pp. 84-91 ◽  
Author(s):  
E. Shafiei ◽  
A. Soltani Tehrani

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.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6173
Author(s):  
Chengchuang Tao ◽  
Hongjun Huang ◽  
Ge Zhou ◽  
Bowen Zheng ◽  
Xiaojiao Zuo ◽  
...  

The hot deformation behavior and processing maps of the casting NiTi alloy were studied at the deformation temperature of 650–1050 °C and the strain rate of 5 × 10−3–1 s−1 by Gleeble-3800 thermal simulating tester. The variation of the strain rate sensitivity exponent m and the activation energy Q under different deformation conditions (T = 650–1050 °C, ε˙ = 0.005–1 s−1) were obtained. The formability of the NiTi alloy was the best from 800 °C to 950 °C. The constitutive equation of the casting NiTi alloy was constructed by the Arrhenius model. The processing map of the casting NiTi alloy was plotted according to the dynamic material model (DMM) based on the Prasad instability criterion. The optimal processing areas were at 800–950 °C and 0.005–0.05 s−1. The microstructure of the casting NiTi alloy was analyzed by TEM, SEM and EBSD. The softening mechanisms of the casting NiTi alloy were mainly dynamic recrystallization of the Ti2Ni phase and the nucleation and growth of fine martensite.


2014 ◽  
Vol 900 ◽  
pp. 588-591
Author(s):  
Gang Chen ◽  
Wei Chen ◽  
Guo Wei Zhang ◽  
Jing Zhai ◽  
Li Ma ◽  
...  

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.


2012 ◽  
Vol 602-604 ◽  
pp. 2006-2010
Author(s):  
Fei Zhao ◽  
Yan Yan ◽  
Yong Hai Ren

The hot deformation behavior of CL60 rail wheel steel has been studied by employing both processing maps and microstructural observations. Tests are performed at temperatures of 800—1100°C and strain rates of 0.1s-1—5s-1 and the flow stress data obtained from the tests are used to develop processing maps. The microstructural evolution of deformed samples is also examined on the basis of optical microscopic observations. The result indicates that under experimental conditions this alloy shows dynamic recrystallization(RDX) characteristics during hot compression deformation. Both deformation temperatures and strain rates have obvious influence on flow stress and its corresponding peak strain, which increase gradually with decreasing temperature and increasing strain rate. RDX occurred at higher temperature and lower strain rate.


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