scholarly journals A Novel Computational Method of Processing Map for Ti-6Al-4V Alloy and Corresponding Microstructure Study

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1599 ◽  
Author(s):  
Ming Hu ◽  
Limin Dong ◽  
Zhiqiang Zhang ◽  
Xiaofei Lei ◽  
Rui Yang ◽  
...  
Keyword(s):  
Strain Rate ◽  
Phase Field ◽  
Processing Map ◽  
Strain Rate Range ◽  
Microstructural Feature ◽  
Computational Method ◽  
Flow Localization ◽  
Optimal Domain ◽  
Rate Range ◽  
Β Phase

The Arrhenius-type constitutive equation is mostly used to describe flow behaviors of material. However, no processing map has been constructed directly according to it. In this study, a novel computational method was applied for establishing the processing map for Ti-6Al-4V alloy in the temperature and strain rate range of 800–1050 °C and 0.001–10 s−1, respectively. The processing map can be divided into four domains according to its graphic features. Among the four domains, the optimal domain is in the temperature and strain rate range of 850–925 °C and 0.001–0.1 s−1, where peak efficiency η is 0.54 and the main microstructural evolution is DRX (dynamic recrystallization). When the alloy is processed in the α + β phase field, the temperature and strain rate range of 800–850 °C and 3–10 s−1 should be avoided, where instability parameter ξ is negative and the microstructural feature is flow localization. When the alloy is processed in the β phase field, DRV (dynamic recovery) and slight DRX of β phase is the main microstructural characteristics in the range of 1000–1050 °C and 0.001–0.02 s−1. However, flow localization of β phase is the main microstructural feature in the range of 1000–1050 °C and 1–10 s−1, which should be avoided.

A Comparative Study on Johnson Cook, Modified Zerilli–Armstrong and Arrhenius-Type Constitutive Models to Predict High-Temperature Flow Behavior of Ti–6Al–4V Alloy in α + β Phase

2016 ◽  
Vol 35 (3) ◽  
pp. 297-307 ◽  
Author(s):  
Jun Cai ◽  
Kuaishe Wang ◽  
Yingying Han
Keyword(s):  
High Temperature ◽  
Comparative Study ◽  
Strain Rate ◽  
Good Description ◽  
Flow Behavior ◽  
Strain Rate Range ◽  
Type Model ◽  
Rate Range ◽  
Β Phase ◽  
Average Absolute Relative Error

AbstractTrue stress and true strain values obtained from isothermal compression tests over a wide temperature range from 1,073 to 1,323 K and a strain rate range from 0.001 to 1 s–1 were employed to establish the constitutive equations based on Johnson Cook, modified Zerilli–Armstrong (ZA) and strain-compensated Arrhenius-type models, respectively, to predict the high-temperature flow behavior of Ti–6Al–4V alloy in α + β phase. Furthermore, a comparative study has been made on the capability of the three models to represent the elevated temperature flow behavior of Ti–6Al–4V alloy. Suitability of the three models was evaluated by comparing both the correlation coefficient R and the average absolute relative error (AARE). The results showed that the Johnson Cook model is inadequate to provide good description of flow behavior of Ti–6Al–4V alloy in α + β phase domain, while the predicted values of modified ZA model and the strain-compensated Arrhenius-type model could agree well with the experimental values except under some deformation conditions. Meanwhile, the modified ZA model could track the deformation behavior more accurately than other model throughout the entire temperature and strain rate range.

scholarly journals Determination of Constitutive Equation and Thermo–Mechanical Processing Map for Pure Iridium

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1087
Author(s):  
Mi Zhou ◽  
Rui Hu ◽  
Jieren Yang ◽  
Chuanjun Wang ◽  
Ming Wen
Keyword(s):  
Constitutive Equation ◽  
Strain Rate ◽  
Processing Map ◽  
Frictional Coefficient ◽  
Strain Curve ◽  
Strain Rate Range ◽  
Forming Process ◽  
Thermal Compression ◽  
Rate Range ◽  
Temperature Range

Deformation behavior of pure iridium has been studied during thermal compression testing with the help of Gleeble-1500D in the temperature range of 1200 °C~1500 °C and strain rate range of 10−1 s−1~10−2 s−1. Resistance to deformation, microstructural evolution and hot workability of pure iridium have been used to analyze in detail. Frictional coefficient has been used to modify the experimental stress–strain curve of thermal compression test, and it has been found effective in reducing the influence of friction during thermo–mechanical testing. The hyperbolic sine constitutive equation of pure iridium has been established to give a material processing model for numerical simulation. A very high value of activation energy for iridium, 573 KJ/mol, clearly indicates that it is very hard to deform this material. The deformation mechanism of pure iridium is dependent upon temperature as well as strain rate. At low temperature and strain rate (temperature range of 1200 °C~1300 °C and strain rate range of 10−1 s−1~10−2 s−1), dynamic recovery is active while dynamic recrystallization becomes operative as temperature and stain rate are increased. On further increase in temperature and decrease in strain rate (temperature range of 1400 °C~1500 °C and strain rates of 10−2 s−1~10−3 s−1), abnormal grain growth takes place. On the basis of a constitutive model and processing map, suitable forming process parameters (temperature range of 1400 °C~1500 °C and strain rate range of 0.1 s−1~0.05 s−1) for pure iridium have been worked out.

Plastic Deformation at High Temperature and Processing Map of AZ61 Magnesium Alloy

2014 ◽  
Vol 926-930 ◽  
pp. 182-185
Author(s):  
Quan Li ◽  
Wen Jun Liu ◽  
Ren Ju Cheng ◽  
Shan Jiang ◽  
Su Qin Luo ◽  
...  
Keyword(s):  
Strain Rate ◽  
Power Dissipation ◽  
Deformation Behavior ◽  
Processing Map ◽  
Rate Sensitivity ◽  
Strain Rate Range ◽  
Processing Maps ◽  
Rate Range ◽  
Optimum Parameters ◽  
Az61 Magnesium Alloy

The deformation behavior of as-cast AZ61 alloy in the temperature range 300-450°C and in the strain rate range 0.01~5 s−1 has been studied using processing maps. For obtaining the processing map, the variation of the efficiency of power dissipation given by [2m/(m+1)] where ‘m’ is the strain rate sensitivity, is plotted as a function of temperature and strain rate. The map exhibited a domain of dynamic recrystallization (DRX) occurring at 425 °C and 0.1 s−1 which are the optimum parameters for hot working of the alloy.

Flow Behavior and Processing Map of Mg-4Al-3Ca-1.5Zn-1Nd-0.2Mn Magnesium Alloy

2014 ◽  
Vol 915-916 ◽  
pp. 588-592
Author(s):  
Gang Chen ◽  
Wei Chen ◽  
Guo Wei Zhang ◽  
Jing Zhai ◽  
Li Ma
Keyword(s):  
Magnesium Alloy ◽  
Strain Rate ◽  
Processing Map ◽  
Flow Behavior ◽  
Strain Rate Range ◽  
Compression Tests ◽  
Rate Range ◽  
Temperature Range ◽  
Optimal Temperature Range ◽  
Flow Stress Data

Compression tests of Mg-4Al-3Ca-1.5Zn-1Nd-0.2Mn Magnesium alloy as-extruded had been performed in the compression temperature range from 200°C to 350°C and the strain rate range from 0.001 s1to 1 s1and the flow stress data obtained from the tests were used to develop the power dissipation map, instability map and processing map. The optimum parameters for hot working of the alloy had been determined. According to the processing maps, the most optimal temperature range is 280°C to 350°C and most optimal strain rate range is 0.001 S-1to 1 S-1.

Deformation resistance and fracture of iron over a wide strain rate range

2014 ◽  
Vol 56 (8) ◽  
pp. 1569-1573 ◽  
Author(s):  
G. I. Kanel ◽  
S. V. Razorenov ◽  
G. V. Garkushin ◽  
S. I. Ashitkov ◽  
P. S. Komarov ◽  
...  
Keyword(s):  
Strain Rate ◽  
Strain Rate Range ◽  
Deformation Resistance ◽  
Rate Range

Tensile Stress-Strain Curves Modeling of Four Kinds of Solders with Temperature and Rate Dependence

2005 ◽  
Vol 297-300 ◽  
pp. 905-911 ◽  
Author(s):  
Xu Chen ◽  
Li Zhang ◽  
Masao Sakane ◽  
Haruo Nose
Keyword(s):  
Tensile Stress ◽  
Constitutive Model ◽  
Strain Rate ◽  
Constant Strain Rate ◽  
Tensile Tests ◽  
Strain Rate Range ◽  
Rate Dependence ◽  
Strain Rates ◽  
Stress Strain ◽  
Rate Range

A series of tensile tests at constant strain rate were conducted on tin-lead based solders with different Sn content under wide ranges of temperatures and strain rates. It was shown that the stress-strain relationships had strong temperature- and strain rate- dependence. The parameters of Anand model for four solders were determined. The four solders were 60Sn-40Pb, 40Sn-60Pb, 10Sn-90Pb and 5Sn-95Pb. Anand constitutive model was employed to simulate the stress-strain behaviors of the solders for the temperature range from 313K to 398K and the strain rate range from 0.001%sP -1 P to 2%sP -1 P. The results showed that Anand model can adequately predict the rate- and temperature- related constitutive behaviors at all test temperatures and strain rates.

scholarly journals Study on Plastic Deformation Behavior of Mo-10Ta under Ultra-High Strain Rate

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1153
Author(s):  
Ping Song ◽  
Wen-Bin Li ◽  
Yu Zheng ◽  
Jiu-Peng Song ◽  
Xiang-Cao Jiang ◽  
...  
Keyword(s):  
Activation Energy ◽  
High Strain Rate ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Deformation Behavior ◽  
High Strain ◽  
Rate Sensitivity ◽  
Strain Rate Range ◽  
Rate Range ◽  
Strain Relationship

This study investigated the deformation behavior of the Mo-10Ta alloy with a strain rate range of 102–105 s−1. The Split Hopkinson pressure bar (SHPB) experiments were conducted to investigate the influence of deformation conditions on the stress-strain relationship and strain rate sensitivity of the material within a strain rate range of 0.001–4500 s−1. The Shaped Charge Jet (SCJ) forming experiments under detonation loading was conducted to clarify the dynamic response and microstructure evolution of the material within an ultra-high strain rates range of 104–105 s−1. Based on the stress-strain relationship of Mo-10Ta alloy at high temperature (286–873 K) and high strain rate (460–4500 s−1), the influence of temperature and strain rate on the activation energy Q was analyzed. The results indicate that the material strain rate sensitivity increased with the increase in strain rate and strain. Meanwhile, the activation energy Q decreased as the temperature and strain rate increased. The plasticity of the Mo-10Ta alloy under the condition of SCJ forming was substantially enhanced compared with that under quasi-static deformation. The material grain was also refined under ultra-high strain rate, as reflected by the reduction in grain size from 232 μm to less than 10 μm.

Extraordinary High Strain Rate Superplasticity of an Al-Mg-Sc-Zr Alloy Subjected to Equal Channel Angular Pressing

2012 ◽  
Vol 735 ◽  
pp. 295-300
Author(s):  
Elena Avtokratova ◽  
Oleg Sitdikov ◽  
Michael Markushev ◽  
Radik R. Mulyukov
Keyword(s):  
Strain Rate ◽  
Equal Channel Angular Pressing ◽  
High Strain ◽  
Strain Rate Range ◽  
Rate Range ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Excess Phases ◽  
Ultrafine Grained Microstructure ◽  
Zr Alloy

Unique superplastic elongations up to 4100% were achieved at 450°C in the strain rate range of 10-2-10-1s-1for Al-Mg-Sc-Zr alloy with a grain size ~1 μm processed by warm-to-hot equal channel angular pressing. Such a behavior is attributed to the synergy of complementary factors resulted in high homogeneity and stability of ultrafine-grained microstructure and superplastic flow, involving large proportion of high-angle grain boundaries, presence of dispersoids of aluminides of transition metals and negligible amount of coarse excess phases.

scholarly journals Modeling of the Strain Rate Dependency of Polycarbonate’s Yield Stress: Evaluation of Four Constitutive Equations

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Abdullah A. Al-Juaid ◽  
Ramzi Othman
Keyword(s):  
Experimental Data ◽  
Strain Rate ◽  
Yield Stress ◽  
Power Law ◽  
Constitutive Relations ◽  
Stress Sensitivity ◽  
Strain Rate Range ◽  
Rate Dependency ◽  
Rate Range ◽  
Strain Rate Dependency

The main focus of this paper is in evaluating four constitutive relations which model the strain rate dependency of polymers yield stress. Namely, the two-term power-law, the Ree-Eyring, the cooperative, and the newly modified-Eyring equations are used to fit tensile and compression yield stresses of polycarbonate, which are obtained from the literature. The four equations give good agreement with the experimental data. Despite using only three material constants, the modified-Eyring equation, which considers a strain rate-dependent activation volume, gives slightly worse fit than the three other equations. The two-term power-law and the cooperative equation predict a progressive increase in the strain rate sensitivity of the yield stress. Oppositely, the Ree-Eyring and the modified-Eyring equations show a clear transition between the low and high strain rate ranges. Namely, they predict a linear dependency of the yield stress in terms of the strain rate at the low strain rate range. Crossing a threshold strain rate, the yield stress sensitivity sharply increases as the strain rate increases. Hence, two different behaviors were observed though the four equations fit well the experimental data. More experimental data, mainly at the intermediate strain rate range, are needed to conclude which, of the two behaviors, is more appropriate for polymers.

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