The Constitutive Model for High Temperature Flow Behavior of SiC/6168Al Composite

2015 ◽  
Vol 1089 ◽  
pp. 37-41
Author(s):  
Jiang Wang ◽  
Sheng Li Guo ◽  
Sheng Pu Liu ◽  
Cheng Liu ◽  
Qi Fei Zheng
Keyword(s):  
Constitutive Model ◽  
Hot Deformation ◽  
Flow Behavior ◽  
Type Equation ◽  
Strain Rate Range ◽  
Compression Tests ◽  
Stress Strain ◽  
Hollomon Parameter ◽  
Proposed Model ◽  
Relationship Of

The hot deformation behavior of SiC/6168Al composite was studied by means of hot compression tests in the temperature range of 300-450 °C and strain rate range of 0.01-10 s-1. The constitutive model was developed to predict the stress-strain curves of this composite during hot deformation. This model was established by considering the effect of the strain on material constants calculated by using the Zenter-Hollomon parameter in the hyperbolic Arrhenius-type equation. It was found that the relationship of n, α, Q, lnA and ε could be expressed by a five-order polynomial. The stress-strain curves obtained by this model showed a good agreement with experimental results. The proposed model can accurately describe the hot flow behavior of SiC/6168Al composite, and can be used to numerically analyze the hot forming processes.

Constitutive Equation for 3104 Alloy at High Temperatures in Consideration of Strain

2016 ◽  
Vol 35 (6) ◽  
pp. 599-605 ◽  
Author(s):  
Fuqiang Zhen ◽  
Jianlin Sun ◽  
Jian Li
Keyword(s):  
Hot Deformation ◽  
Flow Behavior ◽  
Temperature Correction ◽  
Strain Rates ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Element Analysis ◽  
Hollomon Parameter ◽  
The Finite Element Analysis ◽  
Effects Of Temperature

AbstractThe flow behavior of 3104 aluminum alloy was investigated at temperatures ranging from 250°C to 500°C, and strain rates from 0.01 to 10 s−1 by isothermal compression tests. The true stress–strain curves were obtained from the measured load–stroke data and then modified by friction and temperature correction. The effects of temperature and strain rate on hot deformation behavior were represented by Zener–Hollomon parameter including Arrhenius term. Additionally, the influence of strain was incorporated considering the effect of strain on material constants. The derived constitution equation was applied to the finite element analysis of hot compression. The results show that the simulated force is consistent with the measured one. Consequently, the developed constitution equation is valid and feasible for numerical simulation in hot deformation process of 3104 alloy.

Characterization of Hot Deformation Behavior of Udimet720Li Superalloy Using Processing Map

2014 ◽  
Vol 887-888 ◽  
pp. 1161-1168
Author(s):  
Jian Guo Wang ◽  
Dong Liu ◽  
Tao Wang ◽  
Yan Hui Yang
Keyword(s):  
Strain Rate ◽  
Deformation Behavior ◽  
High Strain ◽  
Flow Behavior ◽  
Strain Range ◽  
Peak Stress ◽  
Strain Rate Range ◽  
Hot Working ◽  
Compression Tests ◽  
Hollomon Parameter

The deformation behavior of a Udimet720Li superalloy under hot compression tests was characterized in the temperature range of 1060~1160°C and strain rate range of 0.001~20s-1. Processing maps were conducted at a series of strains to calculate the efficiency of hot working and to recognize the instability regions of the flow behavior. A Zener-Hollomon parameter is given to characterize the dependence of peak stress on temperature and strain rate. The efficiency of power dissipation of the Udimet720Li superalloy obtained in a strain range of 0.1~0.7 are essentially similar, which indicates that strain does not have a significant influence and the instability region shown in high strain and high strain rates at all temperatures. The regions for the full recrystallization can be divided by the dissolution beginning temperature of primary γ'which are the optimum hot working parameters.

scholarly journals Gleeble-Simulated and Semi-Industrial Studies on the Microstructure Evolution of Fe-Co-Cr-Mo-W-V-C Alloy during Hot Deformation

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2577 ◽  
Author(s):  
Yiwa Luo ◽  
Hanjie Guo ◽  
Jing Guo ◽  
Wensheng Yang
Keyword(s):  
Hot Deformation ◽  
Deformation Temperature ◽  
Texture Evolution ◽  
Flow Behavior ◽  
Cutting Tools ◽  
First Principles Calculation ◽  
Hard Material ◽  
Compression Tests ◽  
Gleeble 3500 ◽  
Relationship Of

Fe-Co-Cr-Mo-W-V-C alloy is one of the most important materials for manufacturing drills, dies, and other cutting tools owing to its excellent hardness. However, it is prone to cracking due to its poor hot ductility during continuous hot working processes. In this investigation, the microstructure characteristics and carbide transformations of the alloy in as-cast and wrought states are studied, respectively. Microstructural observation and first-principles calculation were conducted on the research of types and mechanical properties of carbides. The results reveal that carbides in as-cast Fe-Co-Cr-Mo-W-V-C alloy are mainly Mo2C, VC, and Cr-rich carbides (Cr7C3 and Cr23C6). The carbides in wrought Fe-Co-Cr-Mo-W-V-C alloy consist of Fe2Mo4C, VC, Cr7C3, and a small amount of retained Mo2C. For these carbides, Cr7C3 presents the maximum bulk modulus and B/G values of 316.6 GPa and 2.48, indicating Cr7C3 has the strongest ability to resist the external force and crack initiation. VC presents the maximum shear modulus and Yong’s modulus values of 187.3 GPa and 465.3 GPa, which means VC can be considered as a potential hard material. Hot isothermal compression tests were performed using a Gleeble-3500 device to simulate the flow behavior of the alloy during hot deformation. As-cast specimens were uniaxially compressed to a 70% height reduction over the temperature range of 1323–1423 K and strain rates of 0.05–1 s−1. A constitutive equation was established to characterize the relationship of peak true stress, strain rate, and deformation temperature of the alloy. The calculated results were in a good agreement with the experimental data. In order to study the texture evolution, the microstructures of the deformed specimens were observed, and an optimal deformation temperature was selected. Using the laboratorial optimal temperature (1373 K) in forging of an industrial billet resulted in uniform grains, with the largest size of 17 µm, surrounded by homogenous spherical carbides.

Modeling of Flow Stress for one New Kind of Metastable β Titanium Alloy at High Temperature

2011 ◽  
Vol 311-313 ◽  
pp. 716-721
Author(s):  
Zhe Jun Wang ◽  
Hong Fu Qiang ◽  
Xue Ren Wang
Keyword(s):  
Titanium Alloy ◽  
High Temperature ◽  
Flow Stress ◽  
Constitutive Model ◽  
Flow Behavior ◽  
Accurate Estimate ◽  
Compression Tests ◽  
Stress Strain ◽  
Nonlinear Constitutive Equation ◽  
Peak Value

Based on the characteristics of the flow stress curves for one new kind of metastable Ti2448 titanium alloy from isothermal hot compression tests, the constitutive model was developed to describe the relation between flow stress and strain, strain rate, deformation temperature completely. During this process, the flow behavior of alloy at high temperature undergo flow softening caused by dynamic recovery (DRV) was modeled by the adopted hyperbolic sine function based on the unified viscoplasticity theory, the further drop in flow stress after the peak value in stress-strain curves was assumed to be caused by temperature rise and the constitutive model was modified accordingly. Additionally, the material constants were determined by optimization strategies, which is a new method to solve the nonlinear constitutive equation. The stress-strain curves predicted by the developed constitutive model well agree with experimental results, which confirms that the developed constitutive model gives an accurate estimate of the flow stress of Ti2448 titanium alloy and can provide an effect method to model the flow behavior of metastable titanium alloy at high temperature.

scholarly journals Constitutive Model and Flow Behavior of B1500HS High-Strength Steel During the Hot Deformation Process

Metals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 64 ◽  
Author(s):  
Li ◽  
Duan ◽  
Yao ◽  
Guan ◽  
Yang
Keyword(s):  
Flow Stress ◽  
Constitutive Model ◽  
Hot Deformation ◽  
High Strength Steel ◽  
Deformation Behavior ◽  
Flow Behavior ◽  
Constitutive Models ◽  
High Strength ◽  
Stress Strain ◽  
Comparison Results

Hot compression tests were carried out on a Gleeble-3800 thermal mechanical simulator in the temperature range from 700 to 900 °C and strain rate range from 0.005 to 10 s−1 to investigate the hot deformation behavior of B1500HS high-strength steel. Softening mechanisms of B1500HS high-strength steel under different deformation conditions were analyzed according to the characteristics of flow stress–strain curves. By analyzing and processing the experimental data, the values of steady flow stress, saturated stress, dynamic recovery (DRV) softening coefficient, and other factors were solved and these parameters were expressed as functions of Zener–Hollomon factors. Based on the dislocation density theory and the kinetic model of dynamic recrystallization (DRX), constitutive models corresponding to different softening mechanisms were established. The flow stress–strain curves of B1500HS predicted by a constitutive model are in good agreement with the experimental results and the correlation coefficient is . The comparison results indicate that the constitutive models can accurately reflect the deformation behavior of B1500HS high-strength steel under different conditions.

scholarly journals MODIFIED PHYSICALLY-BASED CONSTITUTIVE MODEL FOR As-CAST Mn18Cr18N AUSTENITIC STAINLESS STEEL AT ELEVATED TEMPERATURES

2021 ◽  
Vol 55 (2) ◽  
pp. 243-251
Author(s):  
Jihong Tian ◽  
Fei Chen ◽  
Fengming Qin ◽  
Jiansheng Liu ◽  
Huiqin Chen
Keyword(s):  
Stainless Steel ◽  
Flow Stress ◽  
Austenitic Stainless Steel ◽  
Constitutive Model ◽  
Hot Deformation ◽  
Elevated Temperatures ◽  
Strain Rate Range ◽  
Compression Tests ◽  
Recovery Coefficient ◽  
Physically Based

The hot-deformation behavior of the as-cast Mn18Cr18N high-nitrogen austenitic stainless steel, produced with the electroslag-remelting metallurgical technology, was studied using isothermal-compression tests in a temperature range of 1223–1473 K) and a strain-rate range of 0.001–1 s–1). The flow-stress curves of the Mn18Cr18N steel were obtained under different hot-deformation conditions. By establishing the hyperbolic sine-law Zener-Hollomon equation, the hot-deformation activation energy of the Mn18Cr18N steel was obtained. Based on the mechanism of dislocation evolution, a physically-based constitutive model was established. In addition, the expression of the dynamic-recovery coefficient of the model was modified. Compared with the model before the modification, the modified constitutive model could effectively improve the prediction accuracy of the flow stress for the as-cast Mn18Cr18N austenitic stainless steel.

Constitutive Modeling of Flow Behaviour of AISI 4340 Steel under Hot Working Conditions

2012 ◽  
Vol 249-250 ◽  
pp. 863-869
Author(s):  
Apichat Sanrutsadakorn ◽  
Vitoon Uthaisangsuk ◽  
Surasak Suranuntchai ◽  
Borpit Thossatheppitak
Keyword(s):  
Strain Rate ◽  
Working Conditions ◽  
Elevated Temperatures ◽  
Flow Behavior ◽  
Type Equation ◽  
Hot Working ◽  
Stress Strain ◽  
Hollomon Parameter ◽  
Steel Aisi ◽  
Aisi 4340

Using compression test on a thermo-mechanical simulator/dilatometer, hot deformation behavior of steel AISI 4340 was studied in the temperature range of 850-1150°C and strain rate range of 0.01-10 s-1. The resulted true stress-strain curves exhibited a peak stress at low strain values, after which the flow stresses decreased monotonically until higher strains, representing the dynamic flow softening. The stress level decreased with increasing deformation temperature and decreasing strain rate. The material flow behavior at elevated temperatures was described using a Zener-Hollomon parameter with an exponent-type equation. Additionally, the model was modified by compensating strain rate parameter. The stress-strain responses for the investigated steel predicted by the proposed model agreed well with the experimental results. It was confirmed that the modified constitutive equations provided a more accurate prediction of the flow stress under hot working conditions for steel AISI 4340.

Hot Deformation Behavior of Four Steels: A Comparative Study

2018 ◽  
Vol 140 (2) ◽  
Author(s):  
C. Menapace ◽  
N. Sartori ◽  
M. Pellizzari ◽  
G. Straffelini
Keyword(s):  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Rolling Process ◽  
Peak Strain ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Stress Strain ◽  
Hollomon Parameter ◽  
Experimental Values

The hot deformation behavior of four different steels in the as-cast condition was investigated by means of hot compression tests conducted at temperatures ranging from 1100 °C up to 1200 °C, and at strain rates in between 0.12 and 2.4 s−1. The primary focus of this work was to check the possibility to increase the strain rate during the rough preliminary working of the ingots, i.e., to adopt a rough rolling process in place of the more conventional rough forging. The second aim of the research was to study the influence of the different characteristics of these steels in their as-cast conditions on their hot deformation behavior. It was seen that in all deformation conditions, the stress–strain compression curves show a single peak, indicating the occurrence of dynamic recrystallization (DRX). The hot deformation behavior was studied in both the condition of dynamic recovery (DRV), modeling the stress–strain curves in the initial stage of deformation, and DRX. Data of modeling were satisfactorily employed to estimate the flow stress under different conditions of temperature and strain rate. The experimental values of the activation energy for hot deformation, QHW, were determined and correlated to the chemical composition of the steels; a power law curve was found to describe the relation of QHW and the total amount of substitutional elements of the steels. The critical strain for DRX, εc, was determined as a function of the Zener–Hollomon parameter and correlated to the peak strain, εp. A ratio εc/εp in the range 0.45–0.65 was found, which is in agreement with literature data. All this information is crucial for a correct design of the rough deformation process of the produced ingots.

Flow Behavior and Workability of a Zn-8Cu-0.2Cr Alloy during Hot Deformation

2012 ◽  
Vol 538-541 ◽  
pp. 1257-1261
Author(s):  
Sheng Li Guo ◽  
Peng Du ◽  
Xiao Ping Wu ◽  
De Fu Li
Keyword(s):  
Constitutive Equation ◽  
Strain Rate ◽  
Hot Deformation ◽  
Flow Instability ◽  
Flow Behavior ◽  
Strain Rate Range ◽  
Processing Maps ◽  
Compression Tests ◽  
Rate Range ◽  
Temperature Range

The hot deformation behavior of Zn91.8-Cu8-Cr0.2 (in wt.%) was investigated by means of hot compression tests in the temperature range of 230-380 °C and strain rate range of 0.01 - 10 s-1. The constitutive equation and processing maps were developed. The influence of strain on the flow stress was studied by considering the effect of the strain on material constants. The stress-strain curves obtained by the constitutive equation are in good agreement with experimental results. The proposed constitutive equations can be used for the analysis problem of hot forming processes. The processing maps have exhibited a domain, which is optimum processing window for hot working, in the temperature range of 310 - 380 °C and strain rate range of 0.01-1 s-1 corresponding to the higher efficiency of power dissipation. The large regime of flow instability is observed at high strain rate. The instability regime should be avoided during hot deformation processing.

scholarly journals HOT DEFORMATION BEHAVIOR AND PROCESSING MAP OF A Mg-Gd-Y-Zn-Zr ALLOY

2021 ◽  
Vol 55 (6) ◽  
Author(s):  
Zhaoming Yan ◽  
Jiaxuan Zhu ◽  
Zhimin Zhang ◽  
Qiang Wang ◽  
Yong Xue
Keyword(s):  
Strain Rate ◽  
Flow Behavior ◽  
Type Equation ◽  
Peak Stress ◽  
Material Model ◽  
Processing Parameters ◽  
Compression Tests ◽  
Hollomon Parameter ◽  
Dynamic Material Model ◽  
Deformation Behaviors

Compression tests of a Mg-13Gd-4Y-2Zn-0.5Zr alloy were carried out on a Gleeble-1500D thermo-mechanical simulator within a temperature range of 420–500 °C and strain rate of 0.001–5 s–1 so that the corresponding flow behavior was investigated. The Zener-Hollomon parameter Z was used in a hyperbolic-sine-type equation to express the relationships between the peak stress, deformation temperature and strain rate. Work hardening, dynamic recovery and dynamic recrystallization were the main characteristics affecting the plastic-deformation behaviors. The activation energy Q was calculated to be 208.2 kJ/mol and processing maps at strains of 0.3, 0.5 and 0.7 were generated based on a dynamic material model. The optimum processing parameters were obtained with a power-dissipation analysis.

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