scholarly journals Modified Johnson-Cook Plasticity Model with Damage Evolution: Application to Turning Simulation of 2XXX Aluminium Alloy

2017 ◽  
Vol 33 (6) ◽  
pp. 777-788 ◽  
Author(s):  
H. Ijaz ◽  
M. Zain-ul-abdein ◽  
W. Saleem ◽  
M. Asad ◽  
T. Mabrouki
Keyword(s):  
Grain Size ◽  
Aluminium Alloy ◽  
Fe Simulation ◽  
Damage Model ◽  
Material Model ◽  
Turning Process ◽  
Size Refinement ◽  
Grain Sizes ◽  
Simulation Results ◽  
Material Grain Size

AbstractMechanical properties of the metals and their alloys are influenced by the material grain size at microscale. In the present study, the Johnson-Cook (JC) material model is modified to incorporate the effect of material's grain size along with the plasticity coupled damage model. 2D finite element (FE) simulations of turning process of an aerospace grade aluminium alloy 2024 (AA2024) were performed with different grain sizes using a commercial FE software, ABAQUS/Explicit. FE simulation results were compared with the published experimental data on turning process of AA2024. The proposed modified JC material model successfully simulated the increase in cutting force as a function of grain size refinement.

Prediction of As-Cast Grain Size of Inoculated Multicomponent Aluminum Alloys

2014 ◽  
Vol 790-791 ◽  
pp. 185-190 ◽  
Author(s):  
Qiang Du ◽  
Yan Jun Li
Keyword(s):  
Numerical Simulation ◽  
Grain Size ◽  
Aluminum Alloys ◽  
Cooling Curve ◽  
Restriction Factor ◽  
Grain Sizes ◽  
Cooling Conditions ◽  
Proposed Model ◽  
Simulation Results ◽  
Melt Composition

In this paper, an extendedMaxwell-Hellawell numerical grain size prediction model is employed to predictas-cast grain size of inoculated aluminum alloys. Given melt composition,inoculation and cooling conditions, the model is able to predict maximumnucleation undercooling, cooling curve and final as-cast grain size of multi-componentalloys. The proposed model has been applied to various binary andmulticomponent alloys. Upon analyzing the numerical simulation results, it isfound that for both binary and multi-component alloys, grain size does not havea one-to-one relation with Growth Restriction Factor, Q, but has a clear ubiquitous correlation with the average diffusivity-weightedQ, defined as W in this paper. This founding helps solve the controversy seen inthe recent work on analytical grain size and Q relations. It also has been used to interpret the scatters seenin the measured grain sizes as a function of Q values reported in the literature.

Enhanced Densification and Grain-Size Refinement in Cation-Doped Tetragonal Zirconia

2010 ◽  
Vol 62 ◽  
pp. 227-231
Author(s):  
Keijiro Hiraga ◽  
Hidehiro Yoshida ◽  
Koji Morita ◽  
Byung Nam Kim
Keyword(s):  
Grain Size ◽  
Relative Density ◽  
Grain Growth ◽  
Sintering Temperature ◽  
Initial Density ◽  
Tetragonal Zirconia ◽  
The Other ◽  
Size Refinement ◽  
Grain Sizes ◽  
Materials Used

In tetragonal zirconia, possibility is investigated of densification with finer grain sizes under the combination of doping and sintering in air. The materials used are CIP'ed compacts of 3-mol%-yttria-stabilized tetragonal zirconia (3Y-TZP) doped with a small amount of cations. For a given sintering temperature and initial density of the compacts, while the doped cations enhances densification in the latest stage of sintering, the effect is different in grain growth during densification: a doped cation tended to enhance grain growth, whereas the other cations tended to suppress grain growth. As a result, the doping of the latter cations brings about a grain size finer than that of the undoped 3Y-TZP for a given relative density.

Elimination of membrane compliance in undrained triaxial testing. I. Measurement and evaluation

1993 ◽  
Vol 30 (5) ◽  
pp. 727-738 ◽  
Author(s):  
P.G. Nicholson ◽  
R.B. Seed ◽  
H.A. Anwar
Keyword(s):  
Grain Size ◽  
Test Results ◽  
Factors Affecting ◽  
Grain Sizes ◽  
Wide Range ◽  
Specimen Density ◽  
Thin Membranes ◽  
Alternative Approaches ◽  
Measurement And Evaluation ◽  
Material Grain Size

Several alternative approaches have been suggested for evaluation and correction of the testing errors caused by membrane compliance. The degree to which membrane compliance may affect the results of an undrained test is a function of the soil grain size and overall geometry of the test specimen, as well as specimen density and range of effective confining stresses during a given test. Membrane-compliance effects may be negligible for fine sands and silts tested in conventional 71 mm diameter samples, since even very thin membranes cannot penetrate significantly into the small surficial voids. For medium to coarse sands and gravels, however, membrane-compliance effects may have a significant influence on test results. The scope of this paper is threefold: firstly, to review, examine, and evaluate the variety of methods to measure and characterize membrane compliance; secondly, to develop an improved understanding of the factors affecting membrane compliance; and thirdly, to provide an enhanced, updated, and expanded correlation for estimating membrane compliance characteristics as a function of material grain size for a range of soil types, including a wide range of gradation types and representative grain sizes from silts through gravels. Key words : membrane, penetration, compliance, undrained testing, triaxial, measurement, evaluation.

The Strength and Ductility of 5483 Aluminium Alloy Processed by Various SPD Methods

2013 ◽  
Vol 765 ◽  
pp. 423-428 ◽  
Author(s):  
Piotr Bazarnik ◽  
Barbara Romelczyk ◽  
Mariusz Kulczyk ◽  
Małgorzata Lewandowska
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Mechanical Strength ◽  
Aluminium Alloy ◽  
Microstructural Analysis ◽  
Boundary Misorientation ◽  
Size Refinement ◽  
Specific Strength ◽  
Angular Pressing ◽  
Significant Difference

Grain size refinement is an efficient way to improve mechanical strength and thus make light metals even lighter in terms of specific strength. However, the strength improvement is at the expense of ductility. Therefore, a better understanding of microstructural factors influencing both parameters is of prime importance for further development of ultrafine grained materials. In this work, we report results obtained for 5483 aluminium alloy which was subjected to several severe plastic deformation (SPD) methods, i.e. equal channel angular pressing (ECAP), Hydrostatic Extrusion (HE) and the combination of the two. Detailed microstructural analysis revealed significant difference in the grain size and grain boundary characteristics between samples obtained following different routes. It was found that although the grain size is a prime microstructural parameter determining mechanical strength, second order factors such as grain size distribution and distribution of grain boundary misorientation angles also play a significant role.

Effects of Grain Size on Ballistic Response of Copper Materials

2017 ◽  
Author(s):  
Ge He ◽  
Yangqing Dou ◽  
Xiang Guo ◽  
Yucheng Liu
Keyword(s):  
Grain Size ◽  
High Speed ◽  
Damage Model ◽  
Material Model ◽  
Coarse Grained ◽  
Ballistic Performance ◽  
Fragmentation Behavior ◽  
Constitutive Material Model ◽  
Comparison Results ◽  
The Impact

Numerical simulations were conducted to compare ballistic performance and penetration mechanism of copper (Cu) with four representative grain sizes. Ballistic limit velocities for coarse-grained (CG) copper (grain size ≈ 90 μm), regular copper (grain size ≈ 30 μm), fine-grained (FG) copper (grain size ≈ 890 nm), and ultrafine-grained (UG) copper (grain size ≈ 200 nm) were determined for the first time through the simulations. It was found that the copper with reduced grain size would offer higher strength and better ductility, and therefore renders improved ballistic performance then the CG and regular copper. High speed impact and penetration behavior of the FG and UG copper was also compared with the CG coppers strengthened by nanotwinned (NT) regions. The comparison results showed the impact and penetration resistance of UG copper is comparable to the CG copper strengthened by NT regions with the minimum twin spacing. Therefore, besides the NT regions-strengthened copper, the single phase copper with nanoscale grain size could also be a strong candidate material for better ballistic protection. A computational modeling and simulation framework was proposed for this study, in which Johnson-Cook (JC) constitutive material model is used to predict the plastic deformation of Cu and Ni; JC damage model is to capture the penetration and fragmentation behavior of Cu; Bao-Wierzbicki (B-W) failure criterion defines the material’s failure mechanisms; and temperature increase during this adiabatic penetration process is given by the Taylor-Quinney method.

Improvement of Mechanical Properties of 7475 Aluminium Alloy by the Combination of SPD Processing and Annealing

2011 ◽  
Vol 690 ◽  
pp. 311-314 ◽  
Author(s):  
Kinga Wawer ◽  
Małgorzata Lewandowska ◽  
Krzysztof Jan Kurzydlowski
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Aluminium Alloy ◽  
True Strain ◽  
Hydrostatic Extrusion ◽  
Synergic Effect ◽  
Size Refinement ◽  
Low Temperature Annealing ◽  
Heat Treated ◽  
Precipitate Strengthening

In the present study, SPD processing was combined with annealing in order to obtain synergic effect of grain size refinement and precipitate strengthening. Samples of 7475 alloy were solution heat treated, water quenched and then subjected to hydrostatic extrusion with a total true strain of about 4. Hydrostatic extrusion resulted in a significant grain refinement from 70 mm to about 70 nm. The samples were subsequently annealed at temperatures inducing the formation of nano-precipitates. The investigations of the structure and mechanical properties of the samples subjected to SPD and annealing revealed different precipitation path in micro- and nano-grained samples. Also, it was found that the combination of HE processing and low temperature annealing results in the formation of nano-precipitates in nano-grained structures which effectively strengthen nano-aluminium alloy.

The Effect of Grain Size on the Quality of Micro-Stamping of the Pure Titanium TA1 Foil by Finite Element Simulation

2019 ◽  
Vol 971 ◽  
pp. 3-8
Author(s):  
Rui Chen ◽  
Hong Mei Zhang ◽  
Chang Shun Wang ◽  
Ling Yan ◽  
Yan Li ◽  
...  
Keyword(s):  
Grain Size ◽  
Finite Element ◽  
Surface Morphology ◽  
Finite Element Simulation ◽  
Pure Titanium ◽  
Grain Sizes ◽  
Good Surface ◽  
Element Simulation ◽  
Simulation Results

Pure titanium TA1 foil with a thickness of 0.05mm under different grain sizes were carried out by the DT-C539 micro-stamping machine in the laboratory. The size effect of the pure titanium TA1 foil with grain sizes of 3, 7, 9 and 23 microns respectively on surface morphology of the microstamping sample were studied. It is found that the stamping samples with good surface quality can be obtained on the condition that the grain size is 23 microns and the stamping speed is 1mm/s. VORONOI model was established by using ABAQUS, NEPER and MATLAB software. Heterogeneous finite element simulation was carried out for the micro-stamping process under the same conditions. The results showed that the simulation results were more consistent with the experimental results.

scholarly journals Effect of Grain Size on the Hydrogen Diffusion Process in Steel Using Cellular Automaton Approach

2012 ◽  
Vol 706-709 ◽  
pp. 1568-1573 ◽  
Author(s):  
N. Yazdipour ◽  
D.P. Dunne ◽  
Elena V. Pereloma
Keyword(s):  
Grain Size ◽  
Cellular Automaton ◽  
Hydrogen Diffusion ◽  
High Strength ◽  
Hydrogen Uptake ◽  
Grain Sizes ◽  
Ca Model ◽  
Simulation Results ◽  
Do So

The role of microstructure in susceptibility to hydrogen uptake and property degradation is being evaluated using a number of high strength pipeline steels. To do so, a cellular automaton (CA) model has been used to examine the effect of grain size, as a first step in assessing the influence of microstructure. The simulation results of hydrogen diffusion into microstructures with different grain sizes are presented.

scholarly journals STUDY OF INFLUENCE OF TEMPERATURE-TIME FACTORS ALUMINIUM ALLOY STUCTURE АД31 Al-Mg-Si SYSTEM

2020 ◽  
pp. 64-68
Author(s):  
O. B. Kryuchkov ◽  
A. F. Trudov ◽  
D. A. Mordvintseva ◽  
Yu. Yu. Turapin ◽  
A. A. Bochinskaya
Keyword(s):  
Grain Size ◽  
Aluminium Alloy ◽  
Mechanical Treatment ◽  
Time Factors ◽  
Simultaneous Increase ◽  
High Temperature Annealing ◽  
Influence Of Temperature ◽  
Grain Sizes ◽  
Average Grain Size ◽  
Temperature Time

The results of the study of macro and microstructure, grain sizes and their dispersion, as well as the degree of transformation of α and β iron phases, in cylindrical blanks with diameter of 0.203 m and length of 6.4 m from aluminium alloy АД31 Al-Mg-Si system obtained according to the technology: Melting, semi-continuous casting, mechanical treatment, homogenization annealing at temperatures of 560, 570 and 590 оС with subsequent holding for 0.5 h and cooling together with furnace, fan, sprayer and in water. It has been found that the highest cooling rate and lowest average grain size and dispersion are observed downwards for media: water, sprayer, fan, oven. It has been found that high temperature annealing at a temperature of 590 ° C is more effective than annealing at temperatures of 560 and 570 ° C, which is due to a decrease in the number of iron phases with a simultaneous increase in the proportion of trans-formed inclusions.

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