scholarly journals The Microstructure Evolution of Thermal Deformation of Continuous Extrusion Copper Bus Bar

2018 ◽  
Vol 228 ◽  
pp. 04006
Author(s):  
Jing Lu ◽  
Gaosheng Fu ◽  
Zhimeng Ren ◽  
Jie Liu ◽  
Huan Hao
Keyword(s):  
Grain Size ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Deformation Temperature ◽  
Thermal Deformation ◽  
Raw Material ◽  
Test Machine ◽  
Deformation Microstructure ◽  
Average Grain Size ◽  
Continuous Extrusion

The thermal deformation microstructure of continuous extrusion copper bus bar was observed and analyzed in the temperature range from 200°C to 700°C and at strain rate from 0.01s-1 to 10.0s-1 and at deformation amount from30% to 90% on Gleeble1500 test machine. The experiment results show that the higher the temperature, the lower the strain rate, the more dynamic recrystallization occurred. At the same strain rate, the copper bus bar changes from raw material of as-cast organization to recrystallization grain gradually as the deformation temperature and deformation degree increase, and the recrystallization grain size grows older with the rise of temperature. At the same deformation temperature, the temperature of recrystallization nucleation decreases while the strain rate increases. At low strain rate (0.01~1.0s-1), the dynamic recrystallization occurred at 500°C. While at high strain rate (10.0s-1), the recrystallization nucleation is advanced and it is already completed at 500°C. The Z parameters can be used to express the effect of deformation temperature and strain rate on the average grain size D, and the prediction model of the thermal deformation microstructure is obtained as follows: lnD=4.822-0.018lnZ

scholarly journals Simulation of Dynamic Recrystallization Behavior under Hot Isothermal Compressions for as-extruded 3Cr20Ni10W2 Heat-Resistant Alloy by Cellular Automaton Model

2018 ◽  
Vol 37 (7) ◽  
pp. 635-647 ◽  
Author(s):  
Le Li ◽  
Li-yong Wang
Keyword(s):  
Grain Size ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Cellular Automaton ◽  
Deformation Temperature ◽  
Experimental Result ◽  
Recrystallization Behavior ◽  
Dynamic Recrystallization Behavior ◽  
Ca Model ◽  
Recrystallized Grain Size

AbstractIn order to study dynamic recrystallization behavior of the as-extruded 3Cr20Ni10W2 under isothermal compression conditions, a cellular automaton (CA) model was applied to simulate hot compression. Analysis on the strain–stress curves indicates that dynamic recrystallization is the main softening mechanism for the 3Cr20Ni10W2 when the deformation occurred in the temperature range of 1203–1303 K with an interval of 50 K and strain rate range of 0.01–10 s−1. The deformation temperature and strain rate have a significant influence on the dynamically recrystallized grain size. Subsequently, a CA model is established to simulate the dynamic recrystallization behaviors of the studied alloy. The simulated results show that the mean grain size increases with the increased deformation temperature and decreases with the increased strain rate, which is consistent with the experimental result. In addition, the average absolute relative error, which is 13.14%, indicates that the process of the dynamic recrystallization and the dynamically recrystallized grain size can be well predicted by the present CA model.

Compressing Deformation and Microstructure of AZ61 Magnesium Alloy

2014 ◽  
Vol 1015 ◽  
pp. 203-206
Author(s):  
Quan Li ◽  
Jin Yang ◽  
Wen Jun Liu ◽  
Su Qin Luo ◽  
Ren Ju Cheng ◽  
...  
Keyword(s):  
Grain Size ◽  
Flow Stress ◽  
Magnesium Alloy ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Deformation Temperature ◽  
Hot Compression ◽  
Compression Tests ◽  
Az61 Magnesium Alloy

Hot compression tests of AZ61 magnesium alloy were performed on gleeble1500D at strain rate ranged in 0.01~1s-1 and deformation temperature 350~400°C.The results show that the flow stress and microstructures strongly depend on the deformation temperature and the strain rate. When the temperature was reduced and the strain rate was enhanced, the area after dynamic recrystallization was enhanced, and the average dynamically recrystallied grain size reduce. But the dynamically recrystallied grain size was not well-proportioned. In this paper the 350°C×1s-1 was suggested.

Thermal Deformation Property and Constitutive Model of AZ80 Magnesium Alloy

2013 ◽  
Vol 712-715 ◽  
pp. 674-677
Author(s):  
Fang Wang ◽  
Zhong Tang Wang
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Constitutive Model ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Thermal Deformation ◽  
Deformation Property ◽  
Az80 Magnesium Alloy ◽  
Calculation Results ◽  
Relative Errors

Thermal Deformation Property and Constitutive Model of AZ80 Magnesium Alloy had been studied with thermal simulation experiment. Dynamic recrystallization for AZ80 magnesium alloy had occurred under different strain rate at 583K(310°C). Dynamic recrystallization had occurred more completely and the grain size was reducing with increasing of strain rate. Dynamic recrystallization had occurred more completely and the grain size was reducing with increasing of strain rate. According the Arrhenius equation, a kind of constitutive equation of AZ80 Magnesium alloy which considered the strain had been put forward, and the relative errors between calculation results by the stress-strain model and experiment results are less than 10.5%.

scholarly journals Description of Grain Refinement by Dynamic Recrystallization Under Hot Compressions for As-Extruded 3Cr20Ni10W2 Heat-Resistant Alloy

2015 ◽  
Vol 34 (7) ◽  
pp. 697-713
Author(s):  
Guo-Zheng Quan ◽  
An Mao ◽  
Zhen-Yu Zou ◽  
Gui-Chang Luo ◽  
Jian-Ting Liang
Keyword(s):  
Grain Size ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Strain Rates ◽  
Heat Resistant Alloy ◽  
Resistant Alloy ◽  
Heat Resistant ◽  
Average Grain Size ◽  
Wide Range ◽  
Average Size

Abstract The dynamic recrystallization (DRX) behavior of as-extruded 3Cr20Ni10W2 heat-resistant alloy was investigated by hot compressions with a fixed height reduction of 60% over a temperature range from 1,203 to 1,403 K and a strain rate range from 0.01 to 10 s−1. Results show that DRX occurs more easily at lower temperatures and higher strain rates, the stress level increases significantly with the increase of deformation temperature or the decrease of strain rate. Under such wide range of deformation conditions the flow stress evolution generally indicates two characteristics: work hardening (WH) followed by DRX, or by dynamic recovery (DRV). The variation of the average size of grains refined by DRX behavior in the alloy is characterized by linking the deformation conditions during hot compression process. At a fixed temperature, the average grain size linearly decreases with increasing strain rate in log scale. At a lower strain rate, the average grain size rapidly increases with increasing temperature, while it remains almost constant at strain rate of 10 s−1. At a higher strain rate, grain size data sets tend to be closer to the average size value, which indicates that as strain rate increases, the microstructures become more and more uniform. The effects of the temperatures and strain rates on the average grain size can be represented by Zener–Hollomon parameter, Z, and the relationships between the average grain size and Z parameter can be described as a nonlinear equation, which indicates that the average grain size decreases with increasing Z parameter. On the plot of average grain size D A $${D_A}$$ – l n Z $${\rm{ln}}\,Z$$ , the regions corresponding to DRV ( l n   Z ≤ 77.9 $${\rm{ln}}\ Z\,\le \,77.9$$ ) and DRX ( l n   Z > 77.9 $${\rm{ln}}\ Z\,\gt \,77.9$$ ) were clarified clearly.

Influnce of Grain Size on Dynamic Recrystallization of AZ31 Magnesium Alloy Rolling Sheet

2013 ◽  
Vol 395-396 ◽  
pp. 218-222 ◽  
Author(s):  
Chen Yang Xu ◽  
Fu Xiang Chu ◽  
Xiao Ling Xu ◽  
Hao Chen ◽  
Fang Gao
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Microstructure Evolution ◽  
Deformation Temperature ◽  
Az31 Magnesium Alloy ◽  
Deformation Condition ◽  
Evolution Characteristics ◽  
C 30

Microstructure evolution characteristics and the influence of the intial grain size on the dynamic recrystallization of AZ31 were investigated by rolling at deformation temperature of 280 °C, 30% reduction and strain rate of 5.6s-1. The results indicate that under the present deformation condition, when the grain size is 6.2μm the dynamic recrystallization does not occur , twinning dynamic recrystallization (TDRX) occurs when the original grain size are of 7.9μm and 12.7μm, when the original grain size is 21.1μm rotating dynamic recrystallization (RDRX) occurs.

Study on Dynamic Recrystallization Behavior in Deformed Austenite of 52100 Steel by Using JMAK-Model

2013 ◽  
Vol 275-277 ◽  
pp. 1833-1837
Author(s):  
Ke Lu Wang ◽  
Shi Qiang Lu ◽  
Xin Li ◽  
Xian Juan Dong
Keyword(s):  
Grain Size ◽  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Volume Fraction ◽  
True Strain ◽  
Strain And Strain Rate ◽  
Average Grain Size ◽  
Dynamic Recrystallization Behavior ◽  
Simulation And Experiment ◽  
Good Agreement

A Johnson-Mehl-Avrami-Kolmogorov (JMAK)-model was established for dynamic recrystallization in hot deformation process of 52100 steel. The effects of hot deformation temperature, true strain and strain rate on the microstructural evolution of the steel were physically studied by using Gleeble-1500 thermo-mechanical simulator and the experimental results were used for validation of the JMAK-model. Through simulation and experiment, it is found that the predicted results of DRX volume fraction, DRX grain size and average grain size are in good agreement with the experimental ones.

Hot Compression Deformation Behavior of Spray-Formed AlSn20Cu Alloy

2021 ◽  
Vol 1035 ◽  
pp. 189-197
Author(s):  
Bao Ying Li ◽  
Bao Hong Zhu
Keyword(s):  
Constitutive Equation ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Phase Distribution ◽  
True Stress ◽  
Hot Compression ◽  
Test Machine ◽  
Hot Compression Deformation ◽  
Compression Deformation

The hot deformation behavior of spray-formed AlSn20Cu alloy during hot compression deformation was studied, and the constitutive equation of AlSn20Cu alloy was established. The samples of spray-formed AlSn20Cu alloy were compressed on Gleeble-3500 thermal simulation test machine. The error of the true stress caused by adiabatic heating effect in the experiment was corrected. The constitutive equation of spray-formed AlSn20Cu alloy could be represented by Zener-Hollomon parameter in a hyperbolic sine function. The results showed that the deformation temperatures and strain rates had a notable effect on the true stress of the alloy. At the identical deformation temperature, the true stress increased with the increase of strain rate. When the strain rate was constant, the stress decreased with the increase of deformation temperature. After hot compression deformation, the tin phase was elongated along the direction perpendicular to the compression axis with short strips and blocks. With the increase of deformation temperature and the decrease of strain rate, Sn phase distribution became more homogeneous.

Superplastic Behavior of a Cu-Cr-Zr Alloy Subjected to ECAP

2016 ◽  
Vol 838-839 ◽  
pp. 404-409
Author(s):  
Roman Mishnev ◽  
Iaroslava Shakhova ◽  
Andrey Belyakov ◽  
Rustam Kaibyshev
Keyword(s):  
Grain Size ◽  
Dislocation Density ◽  
Strain Rate ◽  
Temperature Interval ◽  
Rate Sensitivity ◽  
Tensile Tests ◽  
Superplastic Behavior ◽  
Average Grain Size ◽  
Gauge Section ◽  
Zr Alloy

A Cu-0.87%Cr-0.06%Zr alloy was subjected to equal channel angular pressing (ECAP) at a temperature of 400 °C up to a total strain of ~ 12. This processing produced ultra-fine grained (UFG) structure with an average grain size of 0.6 μm and an average dislocation density of ~4×1014 m-2. Tensile tests were carried out in the temperature interval 450 – 650 °C at strain rates ranging from 2.8´10-4 to 0.55 s-1. The alloy exhibits superplastic behavior in the temperature interval 550 – 600 °C at strain rate over 5.5´10-3 s-1. The highest elongation-to-failure of ~300% was obtained at a temperature of 575 °C and a strain rate of 2.8´10-3 s-1 with the corresponding strain rate sensitivity of 0.32. It was shown the superplastic flow at the optimum conditions leads to limited grain growth in the gauge section. The grain size increases from 0.6 μm to 0.87 μm after testing, while dislocation density decreases insignificantly to ~1014 m-2.

scholarly journals High-Temperature Deformation Behavior and Microstructural Characterization of Ti-35421 Titanium Alloy

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3623 ◽  
Author(s):  
Danying Zhou ◽  
Hua Gao ◽  
Yanhua Guo ◽  
Ying Wang ◽  
Yuecheng Dong ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Phase Region ◽  
Temperature Deformation ◽  
Β Phase ◽  
Α Phase

A self-designed Ti-35421 (Ti-3Al-5Mo-4Cr-2Zr-1Fe wt%) titanium alloy is a new type of low-cost high strength titanium alloy. In order to understand the hot deformation behavior of Ti-35421 alloy, isothermal compression tests were carried out under a deformation temperature range of 750–930 °C with a strain rate range of 0.01–10 s−1 in this study. Electron backscatter diffraction (EBSD) was used to characterize the microstructure prior to and post hot deformation. The results show that the stress–strain curves have obvious yielding behavior at a high strain rate (>0.1 s−1). As the deformation temperature increases and the strain rate decreases, the α phase content gradually decreases in the α + β phase region. Meanwhile, spheroidization and precipitation of α phase are prone to occur in the α + β phase region. From the EBSD analysis, the volume fraction of recrystallized grains was very low, so dynamic recovery (DRV) is the dominant deformation mechanism of Ti-35421 alloy. In addition to DRV, Ti-35421 alloy is more likely to occur in continuous dynamic recrystallization (CDRX) than discontinuous dynamic recrystallization (DDRX).

scholarly journals Effect of Hot Deformation Process Parameters on Microstructure and Corrosion Behavior of 35CrMoV Steel

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1455 ◽  
Author(s):  
Qiumei Yang ◽  
Yajun Zhou ◽  
Zheng Li ◽  
Daheng Mao
Keyword(s):  
Grain Size ◽  
Corrosion Resistance ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Temperature ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Rust Layer ◽  
Corrosion Morphology ◽  
Boundary Area

Hot deformation experiments of as-cast 35CrMoV steel, with strain rates of 0.01 s−1 and 10 s−1, deformation temperatures of 850, 950, and 1050 °C, and an extreme deformation reaching 50%, were carried out using a Gleeble-3810 thermal simulator. Electrochemical corrosion experiments were conducted on the deformed specimens. The microstructure was observed by optical microscope (OM), and the corrosion morphology and corrosion products of the specimens were investigated by scanning electron microscopy (SEM), energy disperse spectroscopy (EDS), confocal laser scanning microscopy (CLSM), and X-ray diffraction (XRD) techniques. The results show that the grain size increased gradually with an increase in the deformation temperature at the same strain rate, whereas the corrosion resistance deteriorated. At the same deformation temperature, the grain size becomes smaller as the strain rate increases, which enhances the corrosion resistance. This is mainly attributed to the fine grains, which can form more grain boundaries, increase the grain boundary area, and accelerate the formation of the inner rust layer at the beginning of corrosion. Moreover, fine grains can also refine the rust particles and enhance the bonding strength between the inner rust layer and the matrix. The denseness and stability of the inner rust layer increases as the corrosion process progresses, thereby improving corrosion resistance.

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