Research on Compressive Behavior and Deformation Heating of 7075-T6 Aluminum Alloy during Hot Compression

2014 ◽  
Vol 887-888 ◽  
pp. 315-318
Author(s):  
Dong Ge Wang ◽  
Rui Bin Mei ◽  
Ban Cai ◽  
Chun Li Zhang ◽  
Li Bao ◽  
...  

The flow stress behavior of the 7075-T6 aluminum alloy was studied through single-pass compression experiment by using MMS-300 simulator within temperature range of 300-450°C and strain rate range of 0.01-40s-1. Then a simulation of compression was carried out and the influence of deformation velocity on load and deformation heating was investigated according to the relationship between stress and strain. The results show that dynamic recrystallization occurs in hot compression of 7075-T6 alloy and the stress-strain curves are presented as wave. Furthermore, the flow stress curves have the same wave period and the fluctuation range increases with an increase of strain rate and a decrease of strain. Increasing of deformation velocity results in higher critical strain but the value decreases when the deformation velocity is much higher. The temperature rise increases with the increase of deformation velocity and decrease of deformation temperature. The maximum of temperature rise is more than about 30°C, so that the deformation heating is significant.

2012 ◽  
Vol 538-541 ◽  
pp. 1687-1692
Author(s):  
Ji Xiang Zhang ◽  
Wei Feng ◽  
Hui Wen ◽  
Guo Yin An

The flow stress behavior of 6016 aluminum alloy was investigated on the condition of temperature range from 420°C to 540°C and strain rate range from 0.001s-1to 1s-1based on hot compression experiment on Gleeble-1500 thermal simulation machine. The result shows that the flow stress of 6016 aluminum alloy decreases with the enhancement of temperature and increases with the increase of strain rate. Especially, the flow stress increases tendency becomes obvious when the strain rate greater than 0.1s-1. Based on the results above, a constitutive equation for flow stress of 6016 aluminum alloy when the temperature is above 420°C is obtained by linear regression.


2015 ◽  
Vol 816 ◽  
pp. 810-817
Author(s):  
Yong Biao Yang ◽  
Zhi Min Zhang ◽  
Xing Zhang

The hot deformation behaviors of Aluminum alloy C919 were studied in the present investigation. The hot compression tests for C919 were carried out in the temperature range of 350°C~470°C and strain rates range of 0.001s-1~1s-1 using GLEEBLE-1500 thermal simulate testing machine. Optical microscopy (OM) was used for the microstructure characterization. The experimental results showed that the flow stress of C919 aluminum alloy decreased with increasing temperature and decreasing strain rates and the flow stress curves tended to increase at a strain rate of 1s-1 with increasing strain, while the flow stresses kept with increasing strain at lower strain rate. The alloys were more prone to dynamic recrystallization with decreasing strain rates during hot deformation. The hot compression behavior of C919 aluminum alloy can be described as hyperbolic sine function corrected Arrhenius relation. The processing maps for the alloy were built at a strain of 0.6. The instability deformation domain occurred at temperatures range from 350°C and 380°C and at a strain rate of 0.1-1s-1. Based on the processing maps and microstructure observations, the optimum hot-working parameters were determined to be at a temperature of 470°C in the strain rate range from 0.1-0.01s−1 for the C919 aluminum alloy.


2015 ◽  
Vol 1095 ◽  
pp. 579-582
Author(s):  
Rui Bin Mei ◽  
Bo Zhang ◽  
B. Cai ◽  
X.Y. Zhang ◽  
Z.T. Zou ◽  
...  

The flow stress behavior of the 7085 aluminum alloy was studied through single-pass compression experiment by using MMS-300 simulator within temperature range of 300-450°C and strain rate range of 0.01-10s-1. Dynamic recrystallization occurs in hot compression of 7085 alloy and the stress-strain curves are presented as wave with higher deformation temperature and strain rate. Increasing of deformation velocity and reducing temperature results in higher peak stress. Then a mathematical model has been developed to predict the stress-strain curves based on phenomenological representation of the curves and the traditional theories for constitutive equations which incorporate the power law. The constitutive equation expressed in terms of peak stress, peak strain and additional parameters to predict flow stress. The stress-strain curves of 7085 alloy predicted by this model are in good agreement with experimental results.


2012 ◽  
Vol 510 ◽  
pp. 154-159
Author(s):  
Biao Guo ◽  
Sui Cai Zhang ◽  
Chang Chun Ge

The hot compressive deformation behavior of the superalloy was investigated at the temperature range from 1050 to 1140 and strain rate range from 0.01 to 10s-1 on Gleeble-1500 thermal simulator. Utilizing hyperbolic sine function and introducing the strain with 4th order polynomial fitting, the constitutive equations of flow stress of spray-forming FGH95 superalloy at high temperature were established. The results show that during the hot compression deformation of the superalloy, the characteristics of dynamic softening were observed, and flow stresses decrease with increasing temperature and decreasing strain rate. The flow stress of the superalloy predicted by the proposed models with 4th order polynomial fit agree with the experimental value well, and the average relative error is 3.64%.


2014 ◽  
Vol 886 ◽  
pp. 109-114
Author(s):  
Xiao Zhang ◽  
Zheng Ren ◽  
Xiu Rong Zhu ◽  
Jing Ren ◽  
Fu Kui Lian ◽  
...  

The behavior of flow stress of Al-Mn alloy during hot compression at the condition of ε=0.05,0.5,5,25s-1 while the temperature range from 300°C to 450°C was studied by Gleblee-3500. The results show that the Al-Mn alloy possess the remarkable characteristic of a peak stress, followed by a steady-state flow stress when deformed in the temperature range from 300°C to 450°C with a strain rates range from 0.05s-1 to 0.5s-1.When the strain rate is higher than 5s-1 dynamic recrystallization will happen. The true stress decrease with increasing compression temperature and increases with the increasing strain rate. A constitution equation which can describe the relationship of ε,T and σ is achieved. Also the activation energy for deformation is calculated.


2013 ◽  
Vol 750-752 ◽  
pp. 2165-2169 ◽  
Author(s):  
Yong Qi Cheng ◽  
Zheng Rong Zhang ◽  
Miao Yan Zheng ◽  
Dong Qiang Mo

The hot compression tests on a Gleeble-1500D thermal mechanics simulator were carried out under the strain rate range of 1~ 0.005s-1 at the temperature range of 873-1373K in order to evaluate the constitutive equation of 5Cr21Mn9Ni4N valve steel. All of the flow stress curves exhibit a single peak stress, after which the stress is followed by a steady state regime. The results indicate that the deforming behavior is strongly depending on the strain rate and the deforming temperature. According the experimental data, the hyperbolic law is used to develop the constitutive equations. In the constitutive equations, the effect of the deforming temperature and the strain rate are represented by the Zener-Hollomam parameter. And the flow stress curves are coinciding with the constitutive equation of .


Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1266
Author(s):  
Lei Yu ◽  
Sida Jiang ◽  
Fuyang Cao ◽  
Hongxian Shen ◽  
Lunyong Zhang ◽  
...  

In this paper, we report the results obtained from the hot compression behaviour of co-spray-formed Al-Si/7075 bimetallic gradient alloys by investigating the five selected layers divided evenly from top to bottom. It was found that with a decrease in the strain rate and an increase in temperature, the hot compression flow stress of deposited alloys decreases gradually, as expected. The relationship between flow stress, temperature and strain rate follows the Arrhenius relationship. The deformation activation energy of the co-spray formed gradient alloy gradually increases from bottom to top in the height direction, which are 100.15, 167.35, 185.54, 208.78 and 220.83 KJ/mol, indicating that the degree of difficulty in the deformation of the alloy is affected by changes in the silicon content of the alloy. Finally, the flow stress constitutive equation is calculated for each layer of alloy material, which is instructive for the subsequent study of the densification process of co-spray-formed gradient alloys.


2011 ◽  
Vol 704-705 ◽  
pp. 223-228 ◽  
Author(s):  
Ronɡ Hua Zhang ◽  
Yon Gan Zhang ◽  
Bao Hong Zhu

The behavior of the flow stress of Al-Fe-V-Si heat-resistant aluminum alloy prepared by spray forming during hot compression deformation was studied. The results show that the true stress-true strain curves of the spray forming Al-Fe-V-Si heat-resistant alloy are characterized by a high true stress occurrence at the early stage of compression, followed by a steady flowing due to recovery and strain softening because of dynamic recrystallization. The flow stress of the alloy decreases with increasing deforming temperature and increases with increasing strain rate. The flow stress of the spray forming Al-Fe-V-Si heat-resistant aluminum alloy during hot compression deforming can be described by constitutive equation in hyperbolic sine function.The deformation activation energy of the alloy during hot deformation by Sellars-Tegart equation is much higher than those of the conventional aluminum alloy. The deformation activation energy decreases with decreasing strain rate at the beginning, then increases with decreasing strain rate. Keywords:Al-Fe-V-Si alloy;heat-resistant aluminum alloy;hot compression deformation;flow stress


Author(s):  
Juuso Terva ◽  
Kati Valtonen ◽  
Pekka Siitonen ◽  
Veli-Tapani Kuokkala

A laboratory sized jaw crusher with uniform movement of the jaws, the dual pivoted jaw crusher, was used to determine the relationship between wear and work. Wear was concentrated on the jaw plates opposing each other and was measured as mass loss of the specimens. Work was measured directly from the force and displacement of the instrumented jaw, which allowed work to accumulate only from the actual crushing events. The tests were conducted with several jaw geometries and with two motional settings, where the relation of compressive and sliding motion between the jaws was varied. The tests showed that the relation between wear and work was constant in many of the tested cases. In certain tests with larger lateral and faster contact speed, wear occurred at relatively lower amounts of work. This behavior was more definite when the relation of wear and work was investigated using modified Archards wear equation. The results indicate that the lower amount of needed work could stem from the material reaching a dynamic situation, where the flow stress becomes increasingly strain-rate dependent.


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