Processing Map for Hot Deformation of Homogenized AZ61 Mg Alloy

2013 ◽  
Vol 716 ◽  
pp. 240-243 ◽  
Author(s):  
Ching Hao Liao ◽  
Horng Yu Wu ◽  
Shyong Lee ◽  
Cheng Tao Wu ◽  
Chui Hung Chiu
Keyword(s):  
Power Dissipation ◽  
Processing Map ◽  
Flow Instability ◽  
Local Maximum ◽  
Mg Alloy ◽  
Deformation Condition ◽  
Maximum Efficiency ◽  
Processing Maps ◽  
Compression Tests ◽  
Az61 Mg Alloy

Based on the experimental results from the hot compression tests of homogenized cast AZ61 Mg alloy, processing maps were constructed by superimposition of the instability maps over the power dissipation maps. The domain with the efficiency of power dissipation reaching a local maximum and flow instability region were identified in the processing maps. The processing map obtained at a strain of 0.6 exhibited only one domain with local maximum efficiency of power dissipation. The microstructure observations showed that variation in microstructure was related to the deformation condition, which was associated with the variation in efficiency of power dissipation.

scholarly journals The Investigation on Flow Behavior of Powder Metallurgy Ti-10V-2Fe-3Al Alloy Using the Prasad Stability Criterion

2019 ◽  
Vol 50 (11) ◽  
pp. 5314-5323 ◽  
Author(s):  
Krystian Zyguła ◽  
Marek Wojtaszek ◽  
Oleksandr Lypchanskyi ◽  
Tomasz Śleboda ◽  
Grzegorz Korpała ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Power Dissipation ◽  
Hot Deformation ◽  
High Efficiency ◽  
Flow Instability ◽  
Flow Behavior ◽  
Material Model ◽  
Instability Criterion ◽  
Processing Maps ◽  
Compression Tests

Abstract The hot deformation behavior of Ti-10V-2Fe-3Al alloy obtained by the powder metallurgy (PM) method was investigated. Material for the research was produced by blending of elemental powders followed by uniaxial hot pressing. Thermomechanical tests of Ti-10V-2Fe-3Al compacts were carried out to determinate the stress-strain relationships at the temperature range of 800 °C to 1000 °C and strain rate between 0.01 and 10 s−1. Based on the dynamic material model (DMM) theory, processing maps at constant strain value were developed using data obtained from hot compression tests. The processing maps were elaborated for the final strain value, which was 0.9, and with flow instability criterion domains applied to it. Two critical regions associated with the flow behavior of the investigated material were revealed. Microstructural changes during hot deformation at various temperatures and strain rates were discussed. The correlation between calculated efficiency of power dissipation, flow instability criterion, and microstructure evolution was determined. The presence of defects was confirmed in regions predicted by the instability maps. The microstructure of the investigated alloy, corresponding to the high efficiency of power dissipation characterized by the occurrence of dynamic recrystallization (DRX) phenomena, was also shown. Additionally, average hardness values in relation to variable process parameters were designated. Based on the conducted studies and analysis, processing windows for Ti-10V-2Fe-3Al alloy compacts were proposed.

scholarly journals Investigation on the Thermal Deformation Behavior of the Nickel-Based Superalloy Strengthened by γ′ Phase

Crystals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 125
Author(s):  
Haiping Wang ◽  
Dong Liu ◽  
Jianguo Wang ◽  
Yongzhao Shi ◽  
Yong Zheng ◽  
...  
Keyword(s):  
Flow Stress ◽  
Power Dissipation ◽  
Deformation Behavior ◽  
Processing Map ◽  
Flow Instability ◽  
True Strain ◽  
Processing Condition ◽  
Strain Rates ◽  
Processing Maps ◽  
Nickel Based Superalloy

The isothermal compression tests of the nickel-based superalloy Waspaloy were carried out under various temperatures from 1040 to 1120 °C and strain rates from 0.01 to 10 s−1 with the height reduction of 60% and the flow stress curves were obtained. The curves show that the flow stress is greatly affected by the temperature and strain rates. Regression analysis of the experimental results was carried out to learn about the deformation behavior through the Arrhenius equation and came to the conclusion that the activation energy of Waspaloy is 669.7 kJ/mol. The constitutive equation of the Waspaloy was constructed. Meanwhile, the processing maps of the Waspaloy for the power dissipation and the flow instability were constructed. The processing map of the power dissipation and the flow instability depicts that the strain plays a major role in the processing maps. The instability zone is prone to appear at higher strain rates with the increasing strains. According to the instability processing map, there are three unsafe regimes around 1040–1120 °C/1.5–10 s−1, 1040–1080 °C/0.02–0.1 s−1 and 1110–1120 °C/0.02–0.3 s−1 that should be avoided during deformation process. The power dissipation maps show that the maximum dissipation is prone to appear at low strain rates (0.01 s−1) when the strain is about 0.1~0.6 while at middle strain rates (0.1–1 s−1) when the strain is over 0.6, and when the true strain is 0.9, the optimum processing condition is around 1060–1120 °C/0.1–1 s−1. The dynamic microstructures under different temperatures and strain rates were also obtained. We concluded that lower strain rates and higher temperatures are more applicable to obtain fully-recrystallized microstructures. Based on the instability maps and the power dissipation maps and the dynamic microstructures, the optimum deformation conditions are determined to be around 1080–1100 °C/0.1–1 s−1 and 1040–1120 °C/0.01 s−1.

Effect of True Strain on Processing Maps for Processed Ni-Based Superalloy below γ΄-Transus Temperature

2014 ◽  
Vol 941-944 ◽  
pp. 1459-1462
Author(s):  
Guo Bao Yang ◽  
Ze Kun Yao ◽  
Yan Hui Liu ◽  
Yang Nan ◽  
Yong Quan Ning
Keyword(s):  
Power Dissipation ◽  
Flow Instability ◽  
True Strain ◽  
Small Strain ◽  
Processing Maps ◽  
Compression Tests ◽  
Homogeneous Microstructure ◽  
Transus Temperature ◽  
Small Decline ◽  
Instability Regime

Isothermal compression tests were carried out on GH4133B superalloy at 940–1060°C (below nominal γ΄-transus temperature of 1080°C) and 0.001–1.0s-1. The processing maps were constructed to evaluate the efficiency of power dissipation (η) and recognize the flow instability regimes. Our investigations demonstrate that true strain takes great effect on processing maps' evolution. At 1020°C/1.0s-1, the efficiency valueηundergoes a small decline at low strains, and then increases linearly from 0.26 to 0.58 at high strains. However, the efficiency value remains high constant (η=0.40) with the increased strain under the condition of 980°C/0.001s-1. As a result, hot deformation can be carried out firstly at 980°C/0.001s-1with small strain about 0.35 and then carried out at 1020°C/1.0s-1to get fine homogeneous microstructure. There are two instability regimes respectively located around 940°C/1.0s-1and 1060°C/0.001s-1when the strains are 0.05–0.40. Moreover, there is another instability regime located around 1060°C/1.0s-1when the strains are 0.45–0.69.

scholarly journals Theoretical-Experimental Analysis of the Workability of the Ni50Cr45N0.6 alloy

2017 ◽  
Vol 62 (1) ◽  
pp. 59-65
Author(s):  
A. Łukaszek-Sołek ◽  
A. Świątoniowski ◽  
K. Celadyn ◽  
J. Sińczak
Keyword(s):  
Strain Rate ◽  
Power Dissipation ◽  
Metal Forming ◽  
Flow Instability ◽  
Deformation Behaviour ◽  
True Strain ◽  
Strain Range ◽  
Rate Sensitivity ◽  
Processing Maps ◽  
Compression Tests

Abstract In this paper, the results of investigations into, and of the analyses of, the hot deformation behaviour of the Ni50Cr45N0.6 alloy were presented. Compression tests were conducted on a Gleeble 3800 thermo-mechanical simulator within the following temperatures range 850-1200°C and within that of the strain rate 1-40 s-1 to the constant true strain of 0.9, for the purpose of fulfilling the objective of obtaining experimental stress date. Those data were taken advantage of for the purpose of calculating the workability parameters, and that means the efficiency of power dissipation η, the flow instability ξ and the strain rate sensitivity m. The processing maps based upon Murty’s criterion were drawn up for the following true strain range: 0.2-0.9, and, subsequently, both processing windows and the flow instability areas were determined. For the alloy being analysed, the most advantageous conditions of metal forming were ascertained within the following range of temperatures: 950-1000°C, and for that of the strain rate amounting to 10-40 s-1, and that because of (occurring at the temperature of 950°C) the peak of the efficiency of power dissipation parameter η, amounting to 22% (in accordance with Murty’s criterion). The flow instability areas identified on the processing maps ought to be avoided in metal forming processes. Experimental rolling tests were also conducted.

Processing Maps for TC18 Titanium Alloy Deformed in α+β Region

2012 ◽  
Vol 490-495 ◽  
pp. 3423-3426 ◽  
Author(s):  
Xin Zhao ◽  
Hong Zhao ◽  
Rui Zhang
Keyword(s):  
Titanium Alloy ◽  
Strain Rate ◽  
Power Dissipation ◽  
Strain Rate Range ◽  
Hot Working ◽  
Maximum Efficiency ◽  
Processing Maps ◽  
Compression Tests ◽  
Rate Range ◽  
Temperature Range

The hot deformation characteristics of TC18 titanium alloy were studied in the temperature range 750-850°C and strain rate range 0.001-1 s-1 by using hot compression tests. Processing maps for hot working are developed on the basis of the variations of efficiency of power dissipation with temperature and strain rate. The results reveal that the flow stress of TC18 is sensitive to strain rate. Processing map at stain of 0.6 reveals two domains: one is centered at 750°C and 0.001s-1; another is centered at 850°C and 0.001s-1. The maximum efficiency is more than 60%. According to the maps, the zone with the temperature range of 750-850°C and strain rate range of 0.01-0.001s-1 may be suitable for hot working

The Change of Processing Maps in Hot Compression Procession for Ti-6.0Al-7.0Nb Biomedical Titanium Alloy

2014 ◽  
Vol 906 ◽  
pp. 254-258
Author(s):  
Yan Hui Liu ◽  
Ze Kun Yao ◽  
Yong Quan Ning ◽  
Hong Zhen Guo ◽  
Zhang Long Zhao
Keyword(s):  
Titanium Alloy ◽  
Power Dissipation ◽  
Flow Instability ◽  
True Strain ◽  
Strain Rates ◽  
Processing Maps ◽  
Compression Tests ◽  
Β Phase ◽  
Different Temperatures ◽  
Biomedical Titanium Alloy

Isothermal compression tests were carried out on Ti-6.0Al-7.0Nb biomedical titanium alloy at the temperatures of 750900°C (all below β phase transition temperature about 1010°C) and strain rates of 0.0011.0s-1. The processing maps were constructed to evaluate the efficiency of power dissipation (η) and recognize the flow instability regimes. True strain takes great effect on the efficiency of power dissipation η under the different temperatures and strain rates. The value of power dissipation η increases from 0.1 to 0.7 in most areas. When the strain is 0.9, the value of power dissipation η in most regimes is from 30% to 40%. There are two instability regimes respectively located around 780°C/1.0s-1 and 860-900°C/0.001-0.01s-1 when the strains are below 0.5. One of the instability regimes disappears when the strains are 0.5-0.7. When the strain is 0.9, there are still two instability regimes. The safe regime located around 780-840°C/0.1-0.01s-1, and hot deformation can be carried out in this area.

High Temperature Deformation Behavior of Strip-Cast AZ31 Mg Alloy

2006 ◽  
Vol 15-17 ◽  
pp. 461-466
Author(s):  
B.H. Lee ◽  
Won Kyu Bang ◽  
Sang Ho Ahn ◽  
Chong Soo Lee
Keyword(s):  
High Temperature ◽  
Processing Map ◽  
Microstructural Analysis ◽  
Processing Condition ◽  
Mg Alloy ◽  
Temperature Deformation ◽  
Maximum Efficiency ◽  
Optimum Processing ◽  
Az31 Mg Alloy ◽  
Strip Cast

In this study, optimum processing conditions for strip-cast AZ31 Mg alloy was investigated on the basis of processing map and microstructural analysis. To obtain the processing map, isothermal compression tests were carried out to a strain of 0.5 at temperatures of 200 ∼ 400°C with the strain rates of 0.01 ∼ 10s-1. It was found that maximum efficiency indicating the optimum processing condition occurred at 300°C and 10s-1. The possible deformation mechanisms operating at high temperature was also discussed.

High Temperature Deformation Mechanisms and Processing Map for Hot Working of Cast-Homogenized Mg-3Sn-2Ca Alloy

2010 ◽  
Vol 638-642 ◽  
pp. 3616-3621 ◽  
Author(s):  
K.P. Rao ◽  
Y.V.R.K. Prasad ◽  
Norbert Hort ◽  
Karl Ulrich Kainer
Keyword(s):  
Strain Rate ◽  
Processing Map ◽  
Volume Fraction ◽  
Flow Instability ◽  
Back Stress ◽  
Hot Working ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Strain Rates ◽  
Compression Tests

The hot working behavior of Mg-3Sn-2Ca alloy has been investigated in the temperature range 300–500 oC and strain rate range 0.0003–10 s-1, with a view to evaluate the mechanisms and optimum parameters of hot working. For this purpose, a processing map has been developed on the basis of the flow stress data obtained from compression tests. The stress-strain curves exhibited steady state behavior at strain rates lower than 0.01 s-1 and at temperatures higher than 350 oC and flow softening occurred at higher strain rates. The processing map exhibited two dynamic recrystallization domains in the temperature and strain rate ranges: (1) 300–420 oC and 0.0003–0.003 s-1, and (2) 420–500 oC and 0.003–1.0 s-1, the latter one being useful for commercial hot working. Kinetic analysis yielded apparent activation energy values of 161 and 175 kJ/mole in domains (1) and (2) respectively. These values are higher than that for self-diffusion in magnesium suggesting that the large volume fraction of intermetallic particles CaMgSn present in the matrix generates considerable back stress. The processing map reveals a wide regime of flow instability which gets reduced with increase in temperature or decrease in strain rate.

Hot Workability Map for Near-α Titanium Alloy Ti-5.6Al-4.8Sn-2Zr-1Mo-0.35Si-0.7Nd

2012 ◽  
Vol 482-484 ◽  
pp. 1453-1456
Author(s):  
Ming Man Li ◽  
Qui Jian Xun ◽  
Shang Zhou Zhang
Keyword(s):  
Titanium Alloy ◽  
Dynamic Recrystallization ◽  
Power Dissipation ◽  
Processing Map ◽  
Flow Instability ◽  
Shear Bands ◽  
Hot Workability ◽  
Adiabatic Shear Bands ◽  
Β Phase ◽  
Power Dissipation Efficiency

The characterizations of hot working behavior of a near-α titanium alloy using the approach of processing maps are described. Processing map in the α+β region exhibit a domain of the globularization process of lamellar structure and α dynamic recrystallization with a power dissipation efficiency of 0.6-0.9. In the β region the map exhibited a domain centered around 1060°C and 0.1 s-1with a power dissipation efficiency of 0.76 where the β phase undergoes dynamic recrystallization. At higher strain rate flow instability occurs in the α+β region due to adiabatic shear bands formation as well as in the β region due to flow inhomogeneity of β phase.

Study on Hot Processing Maps and Flow Instability of 1235 Al Alloy Treated by Different Methods of Purification

2011 ◽  
Vol 399-401 ◽  
pp. 1870-1877
Author(s):  
Gao Sheng Fu ◽  
Wen Duan Yan ◽  
Hong Ling Chen ◽  
Gui Qing Chen ◽  
Chao Zeng Cheng
Keyword(s):  
Strain Rate ◽  
Power Dissipation ◽  
Flow Instability ◽  
Al Alloy ◽  
Processing Maps ◽  
Hot Workability ◽  
Optimum Processing ◽  
Lower Strain ◽  
Power Dissipation Efficiency ◽  
Higher Temperature

Based on the theory of processing map proposed by PRASAD, the power dissipation maps, the hot deformation instability maps and the hot processing maps of 1235 Al alloys treated by different methods of purification were built, and the effects of purification and deformation conditions at elevated-temperature on hot workability of 1235 Al alloy were analyzed. At the same time the optimum processing region and flow instability region were determined. The results show that the hot processing map of 1235 Al alloy has two instability zones in the temperature range of 300-500°C and in the strain rate ranging from 0.01s-1to 10.0s-1up to a true strain of 0.7, that is, one zone lying in the range of lower temperature and higher strain rate, the other zone in the range of higher temperature and mid strain rate. The purification effect has significant impact on hot workability of the alloy. It is found that the optimum processing region of 1235 Al alloy treated by high-efficient purification treatment is present in the range of higher temperature and lower strain rate zone, and its power dissipation efficiency is about 46%; while the optimum processing region of 1235 Al alloys treated by conventional refining treatment is present in the range of mid-temperature and lower strain rate zone or in the range of higher temperature and strain rate zone, and its power dissipation efficiency is about 23-29%. The results of observation of the deformation microstructure of 1235 Al alloy are in accordance with that of the hot processing maps of the alloy, thus showing that the calculation results of the hot processing maps are reliable.

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