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.

The Flow Stress Behavior and Constitutive Equation of Nanometric Al2O3 Particulate Reinforced Al Alloy Matrix Composites

2012 ◽  
Vol 628 ◽  
pp. 7-10 ◽  
Author(s):  
Zhi Min Zhang ◽  
Yong Biao Yang ◽  
Xing Zhang
Keyword(s):  
Flow Stress ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Hot Compression ◽  
Al Alloy ◽  
Matrix Composites ◽  
Alloy Matrix ◽  
Stress Behavior ◽  
Flow Stress Behavior ◽  
Particulate Reinforced

The flow stress behavior and constitutive equation of the nanometric Al2O3particulate reinforced Al alloy matrix composites were investigated in the temperature range from 590k-710k, and at the strain rates range from 0.01s-1-1s-1. Hot compression tests were carried out with thermal simulation machine Gleeble-1500. The results showed that the values of the true stresses rose rapidly and then held constant to some extent after attaining the peak values with the increasing strains at different deformation condition. The flow stress for the composites increased with increasing strain rate, which means that the experimental material is a sensitive material of positive strain rate, and decreased with decreasing temperature. Dynamic recovery and dynamic recrystallization occurred during hot compression of the composites. The constitutive equation represented by a Zener-Hollomon parameter in an exponent-type and the deformation activation energy are as follows respectively: σ=71.43ln{(Z/4.37×1011)1/5.94+[(Z/4.37×1011)2/5.94+1]1/2}, Q=197KJ mol-1.

scholarly journals Hot Workability of 300M Steel Investigated by In Situ and Ex Situ Compression Tests

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 880 ◽  
Author(s):  
Rongchuang Chen ◽  
Haifeng Xiao ◽  
Min Wang ◽  
Jianjun Li
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Hot Working ◽  
Ex Situ ◽  
Lower Strain Rate ◽  
Hot Workability ◽  
Compression Tests ◽  
300M Steel ◽  
Lower Strain

In this work, hot compression experiments of 300M steel were performed at 900–1150 °C and 0.01–10 s−1. The relation of flow stress and microstructure evolution was analyzed. The intriguing finding was that at a lower strain rate (0.01 s−1), the flow stress curves were single-peaked, while at a higher strain rate (10 s−1), no peak occurred. Metallographic observation results revealed the phenomenon was because dynamic recrystallization was more complete at a lower strain rate. In situ compression tests were carried out to compare with the results by ex situ compression tests. Hot working maps representing the influences of strains, strain rates, and temperatures were established. It was found that the power dissipation coefficient was not only related to the recrystallized grain size but was also related to the volume fraction of recrystallized grains. The optimal hot working parameters were suggested. This work provides comprehensive understanding of the hot workability of 300M steel in thermal compression.

scholarly journals Mechanical Properties of Al Matrix Composite Enhanced by In Situ Formed SiC, MgAl2O4, and MgO via Casting Process

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1767
Author(s):  
Yuhong Jiao ◽  
Jianfeng Zhu ◽  
Xuelin Li ◽  
Chunjie Shi ◽  
Bo Lu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Matrix Composite ◽  
Compression Strength ◽  
Casting Process ◽  
Al Alloy ◽  
Pyrolysis Process ◽  
Alloy Matrix ◽  
Al Matrix Composite ◽  
Al Matrix

Al matrix composite, reinforced with the in situ synthesized 3C–SiC, MgAl2O4, and MgO grains, was produced via the casting process using phenolic resin pyrolysis products in flash mode. The contents and microstructure of the composites’ fracture characteristics were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Mechanical properties were tested by universal testing machine. Owing to the strong propulsion formed in turbulent flow in the pyrolysis process, nano-ceramic grains were formed in the resin pyrolysis process and simultaneously were homogeneously scattered in the alloy matrix. Thermodynamic calculation supported that the gas products, as carbon and oxygen sources, had a different chemical activity on in situ growth. In addition, ceramic (3C–SiC, MgAl2O4, and MgO) grains have discrepant contents. Resin pyrolysis in the molten alloy decreased oxide slag but increased pores in the alloy matrix. Tensile strength (142.6 ± 3.5 MPa) had no change due to the cooperative action of increased pores and fine grains; the bending and compression strength was increasing under increased contents of ceramic grains; the maximum bending strength was 378.2 MPa in 1.5% resin-added samples; and the maximum compression strength was 299.4 MPa. Lath-shaped Si was the primary effect factor of mechanical properties. The failure mechanism was controlled by transcrystalline rupture mechanism. We explain that the effects of the ceramic grains formed in the hot process at the condition of the resin exist in mold or other accessory materials. Meanwhile, a novel ceramic-reinforced Al matrix was provided. The organic gas was an excellent source of carbon, nitrogen, and oxygen to in situ ceramic grains in Al alloy.

scholarly journals An Improved Johnson–Cook Constitutive Model and Its Experiment Validation on Cutting Force of ADC12 Aluminum Alloy During High-Speed Milling

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1038
Author(s):  
Xinxin Meng ◽  
Youxi Lin ◽  
Shaowei Mi
Keyword(s):  
Aluminum Alloy ◽  
Flow Stress ◽  
Constitutive Equation ◽  
Constitutive Model ◽  
Strain Rate ◽  
Cutting Force ◽  
High Speed ◽  
Cutting Speed ◽  
Experimental Results ◽  
Element Analysis

Because of the massive work and high cost of milling experiments, finite element analysis technology (FEA) was used to analyze the milling process of ADC12 aluminum alloy. An improved Johnson–Cook (J–C) constitutive equation was fitted by a series of dynamic impact tests in different strain rates and temperatures. It found that the flow stress gradually increases as the strain rate rises, but it decreases as the test temperature rises. Compared with the J–C constitutive model, the predicted flow stress by the improved J–C constitutive model was closer to the experimental results when the strain rate was larger than 8000 s−1 and the temperature was higher than 300 °C. A two-dimensional cycloidal cutting simulation model was constructed based on the two J–C constitutive equations which was validated by milling experiments at different cutting speeds. The simulation results based on the improved J–C constitutive equation were closer to the experimental results and showed the cutting force first increased and then decreased, with cutting speed increasing, reaching a maximum at 600 m/min.

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.

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.

Improvement in Hot Workability of Titanium Matrix Composite by Thermohydrogen Treatment

2010 ◽  
Vol 654-656 ◽  
pp. 835-838 ◽  
Author(s):  
Wei Jie Lu ◽  
Jun Qiang Lu ◽  
Di Zhang ◽  
Hong Liang Hou
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Matrix Composite ◽  
Hot Deformation ◽  
Superplastic Deformation ◽  
Tensile Tests ◽  
Increase Strain Rate ◽  
Hot Workability ◽  
Compression Tests ◽  
Β Phase

Ti-6Al-4V matrix composite (TMC) reinforced with TiB plus TiC was prepared and hydrogenated. Isothermal compression tests and high temperature tensile tests were carried out to study the effect of the hydrogen on hot deformation and superplastic deformation. The flow behaviour and microstructure evaluation of hot deformation was investigated. The results show hydrogen can reduce the flow stress and decrease the deformation temperature or increase the strain rate at the same flow stress level in hot deformation. Hydrogen increasing β phase and promoting dynamic recrystallizaiton (DRX) was considered as the main reasons for hydrogen-induced plasticity in hot deformation. The results of superplastic deformation indicate hydrogen can decrease the superplastic temperature 100°C or increase strain rate one order of magnitude at the same elongation level in superplastic deformation. Hydrogen promoting DRX were considered as the main reason for improvement of superplastic elongation.

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).

Tungsten particles reinforced high-entropy alloy matrix composite prepared by in-situ reaction

2020 ◽  
pp. 158037
Author(s):  
Gang Chen ◽  
Tao Luo ◽  
Shucheng Shen ◽  
Jixiang Zheng ◽  
Xiaotian Tang ◽  
...  
Keyword(s):  
Matrix Composite ◽  
High Entropy Alloy ◽  
Alloy Matrix ◽  
High Entropy ◽  
In Situ Reaction
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