Hot Deformation Characterization of Mg-Sm-Zn-Zr Alloy Using Artificial Neural Network and 3D Processing Map

2016 ◽  
Vol 723 ◽  
pp. 252-257
Author(s):  
Ruo Han Chang ◽  
Zhong Yi Cai ◽  
Chao Jie Che
Keyword(s):  
Processing Map ◽  
Processing Parameters ◽  
Maximum Efficiency ◽  
Strain Rates ◽  
Hot Workability ◽  
Compression Tests ◽  
Bp Network ◽  
Wide Range ◽  
3D Processing ◽  
Zr Alloy

The true stress-strain data from isothermal hot compression tests on Gleeble-1500D thermo mechanical simulator, in a wide range of temperatures (350-450°C) and strain rates (0.001-1s-1), was employed to establish the PSO-BP network prediction model and 3D processing map of Mg-Sm-Zn-Zr alloy. It was found that the PSO-BP model could be efficient and accurate in predicting flow stress, most of relative errors were in the range of -4% to 6%, and the average relative error was found to be 1.52%. Then considering the effect of strain, the 3D processing map was established to characterize the hot workability of the alloy. The 3D processing map exhibited the maximum efficiency domain and the instability domain, which could be used to determine the optimal deformation conditions. The optimum processing parameters of Mg-Sm-Zn-Zr alloy were deformation temperatures of 400-450°C and strain rates of 0.003-0.1s-1.

Characterization of Hot Workability of Boron-Added Modified 9Cr-1Mo Steel (P91B) Using Dynamic Materials Model

2015 ◽  
Vol 830-831 ◽  
pp. 325-328
Author(s):  
Marimuthu Arvinth Davinci ◽  
Dipti Samantaray ◽  
Utpal Borah ◽  
Shaju K. Albert ◽  
Arun Kumar Bhaduri
Keyword(s):  
Processing Map ◽  
Thermomechanical Processing ◽  
Strain Rates ◽  
Hot Workability ◽  
Isothermal Compression ◽  
Compression Tests ◽  
Microstructural Investigation ◽  
Dynamic Materials ◽  
Dynamic Materials Model

Elevated temperature workability of Boron added modified 9Cr-1Mo steel is studied in temperature range 1223-1473K and strain rates of 0.001-10s-1 using Dynamic Materials Model. Towards this end hot isothermal compression tests are carried out and the experimental results are used to obtain processing map. Extensive microstructural investigation is carried out to validate different domains of processing map. On the basis of the microstructurally validated processing map, parameters for the thermomechanical processing of P91B are recommended.

HOT WORKABILITY DURING SUBTRANSUS DEFORMATION AT HIGHER STRAIN RATES OF TC11 ALLOY WITH WIDMANSTĂTTEN MICROSTRUCTURE

2009 ◽  
Vol 23 (06n07) ◽  
pp. 875-880 ◽  
Author(s):  
HONGWU SONG ◽  
SHIHONG ZHANG ◽  
MING CHENG ◽  
FEI MEN ◽  
CHUNLING BAO
Keyword(s):  
Microstructure Evolution ◽  
Flow Behavior ◽  
Peak Stress ◽  
Superplastic Forming ◽  
Processing Parameters ◽  
Stress Axis ◽  
Strain Rates ◽  
Hot Workability ◽  
Compression Tests ◽  
Working Parameters

The effect of processing parameters on hot workability and microstructure evolution during subtransus deformation of TC11 alloy with widmanstăten microstructure was studied using isothermal compression tests. Testing was conducted at strain rates of 0.1-10s-1, temperature ranges 920-980°C and height reductions of 30-70%. The influence of hot working parameters on flow behavior, hot workability and microstructure evolution was systemically investigated. The results showed that all the flow curves exhibited a peak stress at very low strains (<0.1) followed by extensive flow softening. Surface fracture, cavitations and localized shear flow were found to be main factors that limited the hot workability of TC11 alloy. At low strains, lamellar kinking started to occur due to the orientation between the colony α lamellar and stress axis. With deformation continues, reorientation of the lamellar colony occurred and the deformed lamellar became elongated and thinner. At high stains, segmentation and globularization of α lamellar took place to produce a refined microstructure with α grain size around 1 µm that is technologically desirable for secondary processes such as superplastic forming. A microstructure mechanism map based on the previous results was then established and applied to process design considering defect and microstructure control.

scholarly journals Evaluation of Hot Workability of Nickel-Based Superalloy Using Activation Energy Map and Processing Maps

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3629 ◽  
Author(s):  
Oleksandr Lypchanskyi ◽  
Tomasz Śleboda ◽  
Krystian Zyguła ◽  
Aneta Łukaszek-Sołek ◽  
Marek Wojtaszek
Keyword(s):  
Activation Energy ◽  
Hot Deformation ◽  
Strain Rates ◽  
Processing Maps ◽  
Hot Workability ◽  
Compression Tests ◽  
Nickel Based Superalloy ◽  
Deformation Parameters ◽  
Deformation Activation Energy ◽  
Wide Range

The stress-strain curves for nickel-based superalloy were obtained from isothermal hot compression tests at a wide range of deformation temperatures and strain rates. The material constants and deformation activation energy of the investigated superalloy were calculated. The accuracy of the constitutive equation describing the hot deformation behavior of this material was confirmed by the correlation coefficient for the linear regression. The distribution of deformation activation energy Q as a function of strain rate and temperature for nickel-based superalloy was presented. The processing maps were generated upon the basis of Prasad stability criterion for true strains ranging from 0.2 to 1 at the deformation temperatures range of 900–1150 °C, and strain rates range of 0.01–100 s−1. Based on the flow stress curves analysis, deformation activation energy map, and processing maps for different true strains, the undesirable and potentially favorable hot deformation parameters were determined. The microstructural observations confirmed the above optimization results for the hot workability of the investigated superalloy. Besides, the numerical simulation and industrial forging tests were performed in order to verify the obtained results.

scholarly journals Hot deformation behavior and processing map of a novel dilute extruded Mg-Zn-Gd-Y-Nd alloy

2020 ◽  
Vol 01 ◽  
Author(s):  
Z. Abbasi ◽  
R. Ebrahimi
Keyword(s):  
High Temperatures ◽  
Hot Deformation ◽  
Processing Map ◽  
Material Model ◽  
Processing Parameters ◽  
Strain Rate Range ◽  
Parameters Optimization ◽  
Strain Rates ◽  
Compression Tests ◽  
Stress Strain

: The hot deformation response of a new dilute Mg alloy was investigated by means of a series of hot compression tests in the temperature and strain rate range of 375-450°C and 0.001-1 s-1 , respectively. The stress-strain behavior, microstructure evolution and processing parameters optimization were studied carefully. Micro-structural characterization studies conducted on a series of deformed samples using optical microscopy revealed that during hot deformation, the main restoration mechanism was dynamic recrystallization (DRX). In the final microstructure of the material, grain boundaries were thoroughly covered by layers of fine DRXed grains. Moreover, a strong twinning induced necklace structure was the most significant characteristic at high strain rates which was accompanied by smaller grain size in the domain material. Based on the measured stress-strain data, constitutive model was conducted on two regimes of low and high temperatures. Moreover, the processing map of the studied material was obtained and interpreted using dynamic material model (DMM). The processing map was built and divided into a feasible domain at high temperatures in the whole range of strain rates and two separated instable domains in the temperature range of 375 to 435°C at high and low strain rates of 1 and 0.001s-1 .

Hot working of SP-700 titanium alloy with lamellar α + β starting structure using a processing map

2020 ◽  
Vol 111 (4) ◽  
pp. 297-306
Author(s):  
Amir Hosein Sheikhali ◽  
Maryam Morakkabati
Keyword(s):  
Titanium Alloy ◽  
Strain Rate ◽  
Hot Deformation ◽  
Processing Map ◽  
Microstructural Analysis ◽  
Shear Bands ◽  
Alpha Phase ◽  
Strain Rates ◽  
Compression Tests ◽  
Temperature Range

Abstract In this study, hot deformation behavior of SP-700 titanium alloy was investigated by hot compression tests in the temperature range of 700-9508C and at strain rates of 0.001, 0.1, and 1 s-1. Final mechanical properties of the alloy (hot compressed at different strain rates and temperatures) were investigated using a shear punch testing method at room temperature. The flow curves of the alloy indicated that the yield point phenomenon occurs in the temperature range of 800- 9508C and strain rates of 0.1 and 1 s-1. The microstructural analysis showed that dynamic globularization of the lamellar α phase starts at 7008C and completes at 8008C. The alpha phase was completely eliminated from b matrix due to deformation- induced transformation at 8508C. The microstructure of specimens compressed at 8508C and strain rates of 0.001 and 0.1 s-1showed the serration of beta grain boundaries, whereas partial dynamic recrystallization caused a necklace structure by increasing strain rate up to 1 s-1. The specimen deformed at 7008C and strain rate of 1 s-1was located in the instability region and localized shear bands formed due to the low thermal conductivity of the alloy. The processing map of the alloy exhibited a peak efficiency domain of 54% in the temperature range of 780-8108C and strain rates of 0.001- 0.008 s-1. The hot deformation activation energy of the alloy in the α/β region (305.5 kJ mol-1) was higher than that in the single-phase β region (165.2 kJ mol-1) due to the dynamic globularization of the lamellar a phase.

Thermal Deformation Behavior and Processing Map of Al-Mg-Er Alloy

2018 ◽  
Vol 913 ◽  
pp. 30-36
Author(s):  
Ran Liu ◽  
Hui Huang ◽  
Ya Liu ◽  
Li Rong
Keyword(s):  
Flow Stress ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Material Model ◽  
Instability Criterion ◽  
Strain Rates ◽  
Processing Maps ◽  
Hot Workability ◽  
Compression Tests ◽  
Dynamic Material Model

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.

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 Deformation Behavior of Q235 Steel during Isothermal Compression at Elevated Temperature

2015 ◽  
Vol 1088 ◽  
pp. 186-190 ◽  
Author(s):  
Ben Yang ◽  
Zhou Zheng ◽  
Li Xin Wang ◽  
Yong Gang Wu
Keyword(s):  
Constitutive Relation ◽  
True Strain ◽  
Strain Curve ◽  
Strain Rates ◽  
Compression Tests ◽  
Q235 Steel ◽  
Wide Range ◽  
Allowable Range ◽  
Experimental Values ◽  
Jc Model

The isothermal hot compression tests of Q235 steel over a wide range of temperatures (1023-1123 K), strain (0.7) and strain rates (1、5、10 s−1) were performed on Gleeble-1500 system. The results show that when the deformation temperature is constant, as the strain rate increases, the flow stress also increases; Use the JC model to establish constitutive relation equation with true stress-true strain curve. And compare the prediction value of the constitutive relation equation with the experimental values, the relative error between the two is within the allowable range, indicating that the JC model constitutive relation equation applicable for the thermal deformation of Q235 steel.

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.

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