An Improved Arrhenius Constitutive Model and Three-Dimensional Processing Map of a Solution-Treated Ni-Based Superalloy

2016 ◽  
Vol 35 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Hong-Bin Li ◽  
Yun-Li Feng
Keyword(s):  
Flow Stress ◽  
Constitutive Model ◽  
Strain Rate ◽  
Hot Deformation ◽  
Processing Map ◽  
Three Dimensional ◽  
Solution Treated ◽  
Forming Temperature ◽  
Deformation Behaviors ◽  
Dimensional Processing

AbstractThe hot deformation behaviors of a solution-treated Ni-based superalloy are investigated by hot compression tests over wide ranges of strain rate and forming temperature. Based on the experimental data, the effects of forming temperature and strain rate on the hot deformation behaviors are discussed in detail. Considering the effects of strain on material constants, comprehensive constitutive models are developed to describe the relationships between the flow stress, strain rate and forming temperature for the studied superalloy. The three-dimensional processing map is constructed to optimize the hot working parameters. Meanwhile, the microstructures are analyzed to correlate with the processing map. It is found that the flow stress is sensitive to the forming temperature, strain rate and deformation degree. With the increase of forming temperature or the decrease of strain rate, the flow stress significantly decreases. The predicted flow stresses agree well with experimentally measured results, which confirm that the developed constitutive model can accurately estimate the flow stress of the studied superalloy. The three-dimensional processing map shows that the optimum deformation windows for hot working are the domains with 980–1,040°C or 0.001–0.1 $${{\rm{s}}^{- {\rm{1}}}}$$ when the strain is 0.6. Also, it is found that the dynamically recrystallized grain size increases with the increase of forming temperature or the decrease of strain rate.

Hot Deformation Behaviors of SiCp/Al Composites

2014 ◽  
Vol 1058 ◽  
pp. 165-169 ◽  
Author(s):  
Shi Ming Hao ◽  
Jing Pei Xie
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Hot Deformation ◽  
True Strain ◽  
Constant Strain Rate ◽  
Hot Compression ◽  
Compression Tests ◽  
Sensitive Material ◽  
2024 Aluminum Alloy ◽  
Deformation Behaviors

The hot deformation behaviors of 30%SiCp/2024 aluminum alloy composites was studied by hot compression tests using Gleeble-1500 thermomechanical simulator at temperatures ranging from 350-500°C under strain rates of 0.01-10 s-1. The true stress-true strain curves were obtained in the tests. Constitutive equation and processing map were established. The results show that the flow stress decreases with the increase of deformation temperature at a constant strain rate, and increases with the increase of strain rate at constant temperature, indicating that composite is a positive strain rate sensitive material. The flow stress behavior of composite during hot compression deformation can be represented by a Zener-Hollomon parameter in the hyperbolic sine form. Its activation energy for hot deformation Q is 183.251 kJ/mol. The optimum hot working conditions for this material are suggested.

Experimental and Physical-Based Constitutive Model Study of FCC Metal Over Wide Temperature and Strain Rate Ranges

2015 ◽  
Author(s):  
Jianchao Yu ◽  
Gang Wang ◽  
Jianwei Qin ◽  
Maobing Shuai ◽  
Yiming Rong
Keyword(s):  
Aluminum Alloy ◽  
Flow Stress ◽  
Constitutive Model ◽  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Deformation ◽  
True Strain ◽  
Experimental Results ◽  
Deformation Behaviors ◽  
Fcc Metal

Dynamic deformation behaviors of aluminum alloy Al1060 (FCC metal) are studied by the uniaxial compression tests on the Split Hopkinson Pressure Bar over wide temperature and strain rate ranges. The experimental results show that the flow stress is both strain rate and temperature sensitivity. The flow stress decreases with increasing temperature when the strain rate keeps constant. When the temperature keeps constant, the flow stress increases with increasing strain rate. Considering the thermal activation of dislocation gliding in the dynamic deformation process, a physical-based constitutive model is developed based on the experimental results to predict the flows stress of Al1060 at a given strain rate and temperature. The material constants in the constitutive model are determined by the nonlinear genetic algorithm. The true stress-true strain curves predicted by the proposed constitutive models can give good correlations with the experimental results, which confirm that the proposed physical-based constitutive can accurately characterize the dynamic deformation behaviors of the studied aluminum alloy Al1060.

scholarly journals The Parameters Identification of High-Temperature Constitutive Model Based on Inverse Optimization Method and 3D Processing Map of Cr8 Alloy Steel

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2216
Author(s):  
Xuewen Chen ◽  
Tingting Lian ◽  
Bo Zhang ◽  
Yuqing Du ◽  
Kexue Du ◽  
...  
Keyword(s):  
High Temperature ◽  
Flow Stress ◽  
Constitutive Model ◽  
Strain Rate ◽  
Alloy Steel ◽  
Thermal Processing ◽  
Processing Map ◽  
Optimization Method ◽  
Inverse Optimization ◽  
3D Processing

As a novel kind of cold roller steel, Cr8 alloy steel has the characteristics of high hardness, high wear resistance and good toughness, which can effectively prolong the service life of the roller that is an important part of the steel rolling mill. How to accurately define the constitutive model parameters of metal materials is the major problem, because it seriously affects the accuracy of numerical simulation results of the roller hot forming process. In the study of Cr8 alloy steel’s thermal deformation behavior of the present paper, the high temperature compression test was done on a Gleebel-1500D thermal/force simulation testing machine. A novel method of parameter identification was proposed based on inverse optimization. The Hansel–Spittel constitutive model was established by using the inverse optimization method. To carry out the verification on the accuracy of the established constitutive model, the predicted flow-stress of constitutive model was made a contrast to the experimental flow-stress, and the standard statistical parameters were also applied to further evaluation. The results showed a relatively high prediction accuracy of the Hansel–Spittel constitutive model based on the inverse optimization algorithm. Meanwhile, to obtain optimal parameters of Cr8 alloy steel in the thermal processing, 3D thermal processing maps concerning strain-rate, strain and temperature were built based on the dynamic material model. According to the 3D processing map, the most adequate thermal processing parameters of Cr8 alloy steel were obtianed as follows: strain 0.2–0.4, strain-rate 0.05–0.005 s−1, temperature 1100–1150 °C.

Hot Deformation Behaviors of SiCp/2024 Aluminum Composites

2013 ◽  
Vol 833 ◽  
pp. 271-275
Author(s):  
Shi Ming Hao ◽  
Jing Pei Xie
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Hot Deformation ◽  
True Strain ◽  
Constant Strain Rate ◽  
Hot Compression ◽  
Compression Tests ◽  
Sensitive Material ◽  
2024 Aluminum Alloy ◽  
Deformation Behaviors

The hot deformation behaviors of 30%SiCp/2024 aluminum alloy composites was studied by hot compression tests using Gleeble-1500 thermomechanical simulator at temperatures ranging from 350-500 °C under strain rates of 0.01-10 s-1. The true stress-true strain curves were obtained in the tests. Constitutive equation and processing map were established. The results show that the flow stress decreases with the increase of deformation temperature at a constant strain rate, and increases with the increase of strain rate at constant temperature, indicating that composite is a positive strain rate sensitive material. The flow stress behavior of composite during hot compression deformation can be represented by a Zener-Hollomon parameter in the hyperbolic sine form. Its activation energy for hot deformation Q is 153.251 kJ/mol. The optimum hot working conditions for this material are suggested.

Constitutive and Processing Map Analyses of Stainless Steel 316 under Hot Compression

2013 ◽  
Vol 378 ◽  
pp. 178-183
Author(s):  
Chui Hung Chiu ◽  
Horng Yu Wu ◽  
Cheng Tao Wu
Keyword(s):  
Stainless Steel ◽  
Flow Stress ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Power Dissipation ◽  
Hot Deformation ◽  
Processing Map ◽  
Constitutive Law ◽  
Hyperbolic Sine ◽  
Stainless Steel 316

Hot deformation characteristics of stainless steel 316 were investigated at elevated temperatures. Hot compressive tests were carried out in the temperature and strain rate ranges from 800 to 1100 °C and 0.001 to 1 s1, respectively. The flow behaviors showed that the softening mechanisms were related to the dynamic recovery (DRV) and dynamic recrystallization (DRX). The constitutive equation relating flow stress, temperature, and strain rate was obtained based on the peak stress. Constitutive equation was constructed according to the hyperbolic sine constitutive law. The flow stress of stainless steel 316 was fitted well by the constitutive equation of the hyperbolic sine function. The constitutive analysis suggested that the hot deformation mechanism of the stainless steel was dislocation creep. The processing map obtained at a strain of 0.5 exhibited two domains with local maximum efficiency of power dissipation. Variation in efficiency of power dissipation was associated with the variation in ZenerHollomon parameter (Z).

The Constitutive Model and Processing Map for In Situ 5wt% TiB2 Reinforced 7050 Al Alloy Matrix Composite

2013 ◽  
Vol 575-576 ◽  
pp. 11-19 ◽  
Author(s):  
Ming Liang Wang ◽  
Zhe Chen ◽  
Dong Chen ◽  
Yi Wu ◽  
Xian Feng Li ◽  
...  
Keyword(s):  
Flow Stress ◽  
Constitutive Equation ◽  
Constitutive Model ◽  
Strain Rate ◽  
Matrix Composite ◽  
Processing Map ◽  
Al Alloy ◽  
Hot Workability ◽  
Alloy Matrix

This study investigated the constitutive flow behavior and hot workability of in-situ 5wt% TiB2 reinforced 7050 Al alloy matrix composite by hot compression experiments. Based on the experimental results of flow curves, a constitutive model describing the relationship of the flow stress, true strain, strain rate and temperature is proposed. Substantially, it is found the constitutive equation of flow stress is dependent on the strain, strain rate and temperature. The coefficients (E.g., α, n, Q and lnA) in the equation are functions of true strains. The results of the calculated values from constitutive equation are verified to well agree with the experimental values. Furthermore, the processing map of the composite is created in order to determine the hot processing domains. The optimum zones for hot workability and instability regions are identified. In instability domain, the microstructures display the main failure modes as the particle cracking and interface debonding.

Constitutive Characteristic of Hot Deformation for Spray Formed Superalloy GH738

2013 ◽  
Vol 747-748 ◽  
pp. 569-574 ◽  
Author(s):  
Yue Wang ◽  
Zhou Li ◽  
Wen Yong Xu ◽  
Hua Yuan ◽  
Na Liu ◽  
...  
Keyword(s):  
Activation Energy ◽  
Flow Stress ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Hot Deformation ◽  
Flow Curves ◽  
Deformation Activation Energy ◽  
Deformation Behaviors ◽  
Gleeble 3500 ◽  
Equiaxed Grains

The hot deformation behaviors of spray formed superalloy GH738 were investigated by using of Gleeble-3500 simulator in the temperature range of 950~1200, with a strain rate of 0.13~6.5s-1 and reduction of 50%. The corresponding flow curves were determined and hot deformed microstructures were observed. The results showed that the flow stress decreased with increasing deformation temperature or decreasing strain rate. A full dynamic recrystallization microstructures with fine-equiaxed grains were obtained at the temperature of 1100~1150 and strain rate of 2.6~6.5s-1. The hot deformation activation energy Q was 580.81kJ.mol-1, and the constitutive equation was derived by means of linear regression.

Constitutive Modeling for Flow Stress Behavior of Nimonic 80A Superalloy During Hot Deformation Process

2016 ◽  
Vol 35 (3) ◽  
pp. 327-336 ◽  
Author(s):  
Sendong Gu ◽  
Liwen Zhang ◽  
Chi Zhang ◽  
Wenfei Shen
Keyword(s):  
Flow Stress ◽  
Constitutive Model ◽  
Hot Deformation ◽  
Critical Strain ◽  
Volume Fraction ◽  
Constitutive Models ◽  
Avrami Equation ◽  
Peak Strain ◽  
Compression Tests ◽  
Nimonic 80A

AbstractThe hot deformation characteristics of nickel-based alloy Nimonic 80A were investigated by isothermal compression tests conducted in the temperature range of 1,000–1,200°C and the strain rate range of 0.01—5 s–1on a Gleeble-1500 thermomechanical simulator. In order to establish the constitutive models for dynamic recrystallization (DRX) behavior and flow stress of Nimonic 80A, the material constantsα,nand DRX activation energyQin the constitutive models were calculated by the regression analysis of the experimental data. The dependences of initial stress, saturation stress, steady-state stress, dynamic recovery (DRV) parameter, peak strain, critical strain and DRX grain size on deformation parameters were obtained. Then, the Avrami equation including the critical strain for DRX and the peak strain as a function of strain was established to describe the DRX volume fraction. Finally, the constitutive model for flow stress of Nimonic 80A was developed in DRV region and DRX region, respectively. The flow stress values predicted by the constitutive model are in good agreement with the experimental ones, which indicates that the constitutive model can give an accurate estimate for the flow stress of Nimonic 80A under the deformation conditions.

Constitutive Modeling for Elevated Temperature Flow Behavior of ZHMn34-2-2-1 Manganese Brass

2017 ◽  
Vol 872 ◽  
pp. 30-37
Author(s):  
Meng Han Wang ◽  
Kang Wei ◽  
Xiao Juan Li
Keyword(s):  
Constitutive Model ◽  
Strain Rate ◽  
Flow Behavior ◽  
Peak Stress ◽  
Strain Rates ◽  
Hollomon Parameter ◽  
Prediction Ability ◽  
Absolute Relative Error ◽  
Deformation Behaviors ◽  
State Stress

The hot compressive deformation behaviors of ZHMn34-2-2-1 manganese brass are investigated on Thermecmastor-Z thermal simulator over wide processing domain of temperatures (923K-1073K) and strain rates (0.01s-1-10s-1). The true stress-strain curves exhibit a single peak stress, after which the stress monotonously decreases until a steady state stress occurs, indicating a typical dynamic recrystallization. A revised constitutive model coupling flow stress with strain, strain rate and deformation temperature is established with the material constants expressed by polynomial fitting of strain. Moreover, better prediction ability of the constitutive model is achieved by implementation of a simple approach for modified the Zener-Hollomon parameter considering the compensation of strain rate and temperature increment. By comparing the predicted and experimented values, the correlation coefficient and mean absolute relative error are 0.997 and 2.363%, respectively. The quantitative statistical results indicate that the proposed constitutive model can precisely characterize the hot deformation behavior of ZHMn34-2-2-1 manganese brass.

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