Constitutive Equation for Elevated Temperature Flow Behavior of Fe-Cr-Ni Preform Reinforced Al-Si-Cu-Ni-Mg Aluminum Composite

2014 ◽  
Vol 633-634 ◽  
pp. 431-435 ◽  
Author(s):  
Ling Zhan Zhou ◽  
Li Ming Yang ◽  
Yin Jiang Peng ◽  
Xiu Rong Zhu

In this paper, squeeze casting process was adopted to produce the Fe-Cr-Ni preform reinforced Al-Si-Cu-Ni-Mg aluminum composite. And then, T6 heat treatment was conducted to enhance the composite’s performance. After which, isothermal compression tests in temperature range of 473-773 K at an interval of 150 K and strain rate range from 0.001 to 10 s-1 were carried out on Gleeble 3500 thermo-mechanical simulation machine. It is found that, for a specific strain rate, the flow stress decreases markedly with temperature increases. And for a fixed temperature, the flow stress generally increases as the strain rate increases. Based on the experimental true stress-true strain data, the Arrhenius type model was established.

2014 ◽  
Vol 651-653 ◽  
pp. 38-41
Author(s):  
Ling Zhan Zhou ◽  
Li Ming Yang ◽  
Yin Jiang Peng ◽  
Xiu Rong Zhu

Fe-Cr-Ni preform reinforcing aluminum composite was produced by squeeze casting. And then, T6 heat treatment was conducted to enhance the composite’s performance. After which, isothermal compression tests in temperature range of 298 - 473 K at an strain rate range from 0.001 to 10 s-1 were carried out on Gleeble 3500 thermo-mechanical simulation machine. It is found that, for a specific strain rate, the flow stress decreases markedly with temperature increases. And for a fixed temperature, the flow stress generally increases as the strain rate increases. Based on the experimental true stress-true strain data, the Arrhenius type model was established.


2018 ◽  
Vol 37 (1) ◽  
pp. 75-87
Author(s):  
Jun Cai ◽  
Kuaishe Wang ◽  
Jiamin Shi ◽  
Wen Wang ◽  
Yingying Liu

AbstractConstitutive analysis for hot working of BFe10-1-2 alloy was carried out by using experimental stress–strain data from isothermal hot compression tests, in a wide range of temperature of 1,023~1,273 K, and strain rate range of 0.001~10 s–1. A constitutive equation based on modified double multiple nonlinear regression was proposed considering the independent effects of strain, strain rate, temperature and their interrelation. The predicted flow stress data calculated from the developed equation was compared with the experimental data. Correlation coefficient (R), average absolute relative error (AARE) and relative errors were introduced to verify the validity of the developed constitutive equation. Subsequently, a comparative study was made on the capability of strain-compensated Arrhenius-type constitutive model. The results showed that the developed constitutive equation based on modified double multiple nonlinear regression could predict flow stress of BFe10-1-2 alloy with good correlation and generalization.


2018 ◽  
Vol 207 ◽  
pp. 03016
Author(s):  
JinLong Chen ◽  
Hengcheng Liao ◽  
Heting Xu

Flow behavior of Al-2.0wt.%Cu-1.0wt.%Mn aluminum alloy was investigated by hot compressive test using a Gleebe-3800 thermal simulator. The test parameters about temperature and strain rate range from 573K to 773 K and from 0.01s-1 to 5s-1, respectively, and the true strain is up to 0.6. It can be seen that the peak flow stress increases with increasing the strain rate and decreases by deformation temperature. And the deformation activation energy of Al-2.0wt.%Cu-1.0wt.%Mn alloy is 183.02KJ/mol. A constitutive equation has been constructed to predict the hot deformation behavior, and correlate the peak flow stress predicted with strain rate and deformation temperature.


2019 ◽  
Vol 38 (2019) ◽  
pp. 461-475
Author(s):  
Jun Cai ◽  
Meng Wang ◽  
Jiamin Shi ◽  
Kuaishe Wang ◽  
Wen Wang

AbstractConstitutive analysis for elevated temperature flow behavior of BFe10-1-2 alloy was carried out by using experimental stress–strain data from isothermal hot compression tests on a Gleeble-3800 thermo-mechanical simulator, in a wide of temperature range of 1,023–1,273 K, and strain rate range of 0.001–10 s−1. A constitutive equation based on double multiple nonlinear regression (DMNR) was proposed considering the independent effects of strain, strain rate, temperature and their interrelation. The predicted flow stress data obtained from the developed equation based on DMNR was compared with the experimental data. Correlation coefficient (R), average absolute relative error (AARE) and relative errors were introduced to verify the validity of the developed constitutive equation. The results showed that the developed constitutive equation based on DMNR could predict flow stress of BFe10-1-2 alloy with good correlation and generalization.


2014 ◽  
Vol 887-888 ◽  
pp. 1161-1168
Author(s):  
Jian Guo Wang ◽  
Dong Liu ◽  
Tao Wang ◽  
Yan Hui Yang

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.


2014 ◽  
Vol 1058 ◽  
pp. 165-169 ◽  
Author(s):  
Shi Ming Hao ◽  
Jing Pei Xie

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.


2019 ◽  
Vol 51 (1) ◽  
pp. 467-481
Author(s):  
Suwaree Chankitmunkong ◽  
Dmitry G. Eskin ◽  
Chaowalit Limmaneevichitr

Abstract Aluminum piston alloys of the AA4032 type are produced by direct-chill (DC) casting and subsequent forging; therefore, it is important to understand their thermomechanical behavior. In recent years, it was shown that additions of Cu and Er could improve mechanical properties of these alloys at room and high temperatures. In this work, we studied the constitutive behavior of AA4032-type alloys with and without Cu and Er additions. The experimental true stress–true strain curves were obtained by compression tests under various temperatures [683 K to 723 K (410 °C to 450 °C)] and strain rates (0.01 to 10 s−1) to determine constitutive parameters [strain-rate sensitivity, activation energy, and Zener–Hollomon (Z) parameter] for the hot deformation behavior of AA4032-type piston alloys with and without additions of Cu and Er. The flow stress decreased with increasing deformation temperature and decreasing strain rate. The results also showed that increasing the Cu content increased the flow stress over the applied range of deformation conditions due to solid-solution strengthening and the formation of primary Si particles, which led to an increase in the activation energy during hot deformation. Moreover, the main microstructural damage in the AA4032 alloy with 3.5 pct Cu was predominantly due to the cracking of primary Si particles. Additions of 0.4 pct Er and 3.5 pct Cu lower the activation energy of deformation, Q, as compared to the base alloy and the alloy with 3.5 pct Cu. The microstructures in the deformed specimens consisted of subgrains, recrystallized grains, and fine eutectic phases. The alloys containing Er demonstrated more polygonized grains at a low strain rate than the alloys without Er, indicating that Er hindered recrystallization development. The peak stress of the AA4032 alloy with 3.5 pct Cu alloy was higher than for the base AA4032 alloy and for the AA4032 alloy with 3.5 pct Cu and 0.4 pct Er additions, which was attributed to the prevalence of the work-hardening mechanism over the softening mechanism.


2013 ◽  
Vol 17 (5) ◽  
pp. 1523-1528
Author(s):  
Bao-Hua Jia ◽  
Wei-Dong Song ◽  
Hui-Ping Tang ◽  
Jian-Guo Ning

Isothermal compression tests of TC18 titanium alloy at the deformation temperatures ranging from 25?C to 800?C and strain rate ranging from 10-4 to 10-2 s-1 were conducted by using a WDW-300 electronic universal testing machine. The hot deformation behavior of TC18 was characterized based on an analysis of the true stress-true strain curves of TC18 titanium alloy. The curves show that the flow stress increases with increasing the strain rate and decreases with increasing the temperature, and the strain rate play an important role in the flow stress when increasing the temperatures. By taking the effect of strain into account, an improved constitutive relationship was proposed based on the Arrhenius equation. By comparison with the experimental results, the model prediction agreed well with the experimental data, which demonstrated the established constitutive relationship was reliable and can be used to predict the hot deformation behavior of TC18 titanium alloy.


2013 ◽  
Vol 747-748 ◽  
pp. 320-326 ◽  
Author(s):  
Wen Xiang Wu ◽  
Li Jin ◽  
Jie Dong ◽  
Zhen Yan Zhang ◽  
Wen Jiang Ding

The hot deformation behaviors and microstructural evolution of Mg-3.0Nd-0.2Zn-0.4Zr (wt. %, NZ30K) alloy were investigated by means of the isothermal hot compression tests at temperatures of 350-500 °C with strain rates of 0.001, 0.01, 0.1 and 1s-1. The results showed that the flow stress increased to a peak and then decreased which showed a dynamic flow softening. The flow stress behavior was described by the hyperbolic sine constitutive equation with an average activation energy of 193.8 kJ/mol. The average size of dynamically recrystallized grains of hot deformed NZ30K alloy was reduced by increasing the strain rate and/or decreasing the deformation temperature. A large amount of fine particles precipitated in the grains interior and at the grain boundaries when heated to the compression temperatures and soaked for 5min below 450 °C. However, the volume fraction of particles decreased significantly when soaked for 5 min at 500 °C, and the coarse particles precipitated mainly at the grain boundaries. Hot deformation at the temperature of 500 °C around and at the strain rate range of 0.1s-1 was desirable for NZ30K alloy.


2013 ◽  
Vol 274 ◽  
pp. 427-431 ◽  
Author(s):  
Ying Gong

The compression test on TC21 titanium alloy was carried out in the temperature range of 860~940oC and the strain rate range of 0.01~10s-1 on Gleeble-1500D hot simulation machine. And the hot deformation behavior was studied. The processing map was calculated and analyzed according the dynamic materials model. It is found that the flow stress of TC21 decreases with the increasing of the temperature and the decreasing of the strain rate. The flow stress curves are characterized by steady state at low strain rate( s-1)but discontinuous yield at high strain rate( s-1). The processing map established at the true strain of 0.4 shows that there are three regions, instability and safe and peak region, and the efficiencies of power dissipation are 0~25%,31%~37% and 43%~49% respectively. The peak region is the optimum hot working zone of TC21 titanium alloy.


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