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

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.

Author(s):  
Jianchao Yu ◽  
Gang Wang ◽  
Jianwei Qin ◽  
Maobing Shuai ◽  
Yiming Rong

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.


2013 ◽  
Vol 395-396 ◽  
pp. 1026-1030 ◽  
Author(s):  
Zhao Lin Zhong ◽  
Xing Ai ◽  
Zhan Qiang Liu

This paper presents the experimental results of cutting force and surface roughness of 7050-T7451 aluminum alloy under the cutting speed of 3000~5000m/min. The cutting forces and surface roughness with different cutting parameters were analyzed. Experimental results suggested that increasing cutting speed would engender thermal softening, which would in return affect the cutting force and surface roughness in high speed milling. The cutting force and surface roughness were affected by cutting depth and feed rate obviously. Surface roughness was also affected by cutting width which changed the cutting force slightly. According to the results, proper parameters could be selected and thermodynamic relationship needed to be discussed for further research.


2014 ◽  
Vol 494-495 ◽  
pp. 602-605
Author(s):  
Zeng Hui An ◽  
Xiu Li Fu ◽  
Ya Nan Pan ◽  
Ai Jun Tang

Cutting forces is one of the important physical phenomena in metal cutting process. It directly affects the surface quality of machining, tool life and cutting stability. The orthogonal experiments of cutting forces and influence factors with indexable and solid end mill were accomplished and the predictive model of milling force was established during high speed end milling 7050-T7451 aluminum alloy. The paper makes research mainly on the influence which the cutting speed, cutting depth and feed have on the cutting force. The experimental results of single factor showed that the cutting forces increase earlier and drop later with the increase of cutting speed, and the cutting speed of inflexion for 7050-T7451 is 1100m/min. As axial cutting depth, radial cutting depth and feed rate increase, the cutting force grows in different degree. The cutting force is particularly sensitive to axial cutting depth and slightly to the radial cutting depth.


1989 ◽  
Vol 56 (3) ◽  
pp. 514-518 ◽  
Author(s):  
I. U. Mahmood ◽  
M. O. Faruque ◽  
M. M. Zaman

This paper discusses the application of an internal variable, creep constitutive model, where the concept of piecewise linearity in the effective stress-creep strain rate relationship is utilized. Since the concept of piecewise linearity is assumed, an explicit functional form for creep strain rate at all levels of stress and temperature is not required. The aforementioned constitutive model is used to predict the creep response of an aluminum alloy (2618-T61) at 200°C and subjected to multiaxial loading. The results are compared with available experimental results. The model shows excellent agreement in the trend of creep response. The quantitative values also agree quite good with the experimental results.


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.


2011 ◽  
Vol 418-420 ◽  
pp. 1274-1278
Author(s):  
Shu Zhen Shang ◽  
Xiao Ling Tang ◽  
Gui Min Lu ◽  
Wan Ning Zhang ◽  
Jiao Jiao Wang

Effects of deformation temperature and strain rate on deformation behavior of semi-solid ZL201 alloy were investigated on Gleeble3800 thermal-mechanical simulator. On basis of the experimental data of semi-solid ZL201, a model of was established to describe the relationship between the processing parameters and flow stress, which showed that the experimental results and calculation ones fitted well. The suitable conditions of this model for semi-solid ZL201 alloy were that the temperature range was 547°C-649°C and that of the strain rate was 0.1 s-1-5s-1.


2011 ◽  
Vol 228-229 ◽  
pp. 1112-1117 ◽  
Author(s):  
Ji Xiang Zhang ◽  
Hui Wen ◽  
Wei Feng ◽  
Guo Yin An ◽  
Jin Xi Liu

In order to realize numerical simulation of warm forming and reasonably establish the warm formation process parameters for 6016 aluminum alloy, we study the forging process of 6016 aluminum alloy with warm compression experiments on the Gleele-1500 thermal simulation testing machine, and research the deformation flow stress behavior of the aluminum alloy sheet at different temperatures , strain rate under the warm forming. The results show that the deformation temperature and strain rate have significant influence on flow stress of 6016 aluminum alloy sheet, that is, the alloy is a temperature and strain rate sensitive materials, and the flow stress increases with the increase of strain rate and decreases with the increase of deformation temperature. The deformation constitutive equation of 6016 aluminum alloy is got by multiple linear regression analysis. The constitutive equation is consistent with the experimental curves rather well, which confirms the accuracy of the constitutive equation.


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.


2006 ◽  
Vol 532-533 ◽  
pp. 125-128 ◽  
Author(s):  
Xiu Li Fu ◽  
Xing Ai ◽  
Song Zhang ◽  
Yi Wan

Accurately material constitutive model is essential to understand and predict machining process. High temperature split Hopkinson pressure bar (SHPB) test system is used to investigate flow stress behavior and characteristics of 7050-T7451 aluminum alloy. Specimens are tested from 200°C to 550°C at intervals of 50°C and room temperature, at strain-rate of 2800s-1. The experimental results show that flow stress is strongly dependent on temperature as well as strain rate, flow stress decreases with the increase of temperature, while increase with the increasing of strain rate. The material parameters are determined for both Johnson-Cook constitutive equation and modified Johnson-Cook constitutive equation. The modified JC equation is more suitable for expressing the dynamic behavior of 7050-T7451 aluminum alloy.


Mechanik ◽  
2018 ◽  
Vol 91 (10) ◽  
pp. 871-873
Author(s):  
Józef Kuczmaszewski ◽  
Paweł Pieśko ◽  
Magdalena Zawada-Michałowska

The analysis of cutting forces during in-cut and out-cut milling of EN AC-AlSi10Mg cast aluminum alloy was presented. The research included measurement of the components of the total cutting force: Ff, Fp and Fc (Fx, Fy, Fz respectively) and determination of their amplitudes at a constant feed per tooth value and the adopted variable technological parameters, i.e.: depth of cut ap, milling width ae and cutting speed vc. Based on the obtained results, it was found that along with the increase in the depth of cut and the milling width, the values of selected components and their amplitudes increase for both in-cut and out-cut milling. During rise of cutting speed, it was observed that the components of the total cutting force increase to the speed vc = 450 m/min, then their values begin to decrease. This is related to the transition from conventional machining to the range of High Speed Cutting. It is important that higher values of cutting forces were noted in the case of out-cut milling instead of in-cut milling.


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