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.

scholarly journals Numerical simulation for the effects of waves and grain size on deltaic processes and morphologies

2020 ◽  
Vol 12 (1) ◽  
pp. 1286-1301
Author(s):  
Yang Liu ◽  
Hongde Chen ◽  
Jun Wang ◽  
Shuai Yang ◽  
Anqing Chen
Keyword(s):  
Numerical Simulation ◽  
Grain Size ◽  
Numerical Simulations ◽  
Morphological Changes ◽  
Morphological Characteristics ◽  
Simulation Method ◽  
River Channels ◽  
Grain Sizes ◽  
Average Grain Size ◽  
Simulation Results

AbstractCurrently, the sedimentation process concerning the formation of the morphological changes of deltas under the action of waves has received little attention. Two numerical simulations were carried out in this study to explore the sedimentary morphological changes of deltas under wave action. In the first experiment, the morphological characteristics of river-dominated deltas and wave-dominated deltas were compared. Results showed that a wave-dominated delta was more likely to produce slender and stable rivers relative to a river-dominated delta. In the second experiment, the morphologies of wave-dominated deltas with sediments of different grain sizes were compared. Results indicated that delta morphology was not significantly correlated with the median grain size ({\phi }_{50}) of the sediment, and the average grain size of the coarser sediments ({\phi }_{25}) was an important factor affecting delta morphology. Moreover, a delta with a larger {\phi }_{25} value of the input sediment, a smaller topset gradient, and a smaller number of active river channels had a more arcuate shape. The results showed that the hydrodynamic numerical simulation method has the ability to reveal the evolution of deltas under the action of waves. The final simulation results were consistent with the actual delta data.

Modeling Recrystallization for 3D Multi-Pass Forming Processes

2007 ◽  
Vol 558-559 ◽  
pp. 1201-1206 ◽  
Author(s):  
Mihaela Teodorescu ◽  
Patrice Lasne ◽  
Roland E. Logé
Keyword(s):  
Numerical Simulation ◽  
Grain Size ◽  
Present Model ◽  
Static Recrystallization ◽  
Volume Fraction ◽  
The Other ◽  
Finite Element Code ◽  
3D Numerical Simulation ◽  
Fraction Distribution ◽  
Simulation Results

The present work concerns the simulation of metallurgical evolutions in 3D multi-pass forming processes. In this context, the analyzed problem is twofold. One point refers to the management of the microstructure evolution during each pass or each inter-pass period and the other point concerns the management of the multi-pass aspects (different grain categories, data structure). In this framework, a model is developed and deals with both aspects. The model considers the microstructure as a composite made of a given (discretized) number of phases which have their own specific properties. The grain size distribution and the recrystallized volume fraction distribution of the different phases evolve continuously during a pass or inter-pass period. With this approach it is possible to deal with the heterogeneity of the microstructure and its evolution in multi-pass conditions. Both dynamic and static recrystallization phenomena are taken into account, with typical Avrami-type equations. The present model is implemented in the Finite Element code FORGE2005®. 3D numerical simulation results for a multi-pass process are presented.

Monte Carlo Simulation of Seebeck Coefficient and Electrical Conductivity in Thermoelectrics

2013 ◽  
Vol 709 ◽  
pp. 176-179 ◽  
Author(s):  
Jian Li
Keyword(s):  
Electrical Conductivity ◽  
Monte Carlo Simulation ◽  
Grain Size ◽  
Monte Carlo ◽  
Seebeck Coefficient ◽  
Ground State ◽  
Proposed Model ◽  
Average Grain Size ◽  
Polycrystalline Ceramics ◽  
Simulation Results

we proposed a scheme for simulating the electronic and thermoelectric properties of polycrystalline ceramics. The simulation results show that the ground state electrons are easily confined in the largest grain. In addition, with the increasing average grain size, the Seebeck coefficient decreases while the electrical conductivity increases monotonically. The simulation results agree well with the available experimental results. Therefore, the proposed model is proved to be a promising approach for thermoelectric investigations.

scholarly journals Numerical Simulation and Experimental Verification of Dry Pressed MgTiO3 Ceramic Body during Pressureless Sintering

2021 ◽  
Author(s):  
Jiang Wang ◽  
Yu Ni ◽  
Kai Liu ◽  
Yanying Du ◽  
Wei Liu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Grain Size ◽  
Relative Density ◽  
Ceramic Body ◽  
Simulation Method ◽  
Shrinkage Rate ◽  
Pressureless Sintering ◽  
Numerical Simulation Method ◽  
Average Grain Size ◽  
Simulation Results

Abstract To clarify the densification law of dry pressed MgTiO3 ceramic body during pressureless sintering, SOVS model modified with creep characteristics was embedded into finite element software Abaqus. The selected model can effectively express the grain boundary characteristics and densification mechanism. The change law of relative density, shrinkage rate, sintering stress and grain size of MgTiO3 cylindrical specimens were investigated by the above numerical simulation method. It showed that the average relative density of ceramic body rose from 60% to 97% and the shrinkage rate resepectively reached 17.28% and 11.99% in axial and radial direction. The average grain size increased from 1μm to 6 μm. In order to verify the accuracy of the simulation results, corresponding sintering experiments on cylindrical specimens were carried out to obtain actual sintering densities and shrinkage rates. It showed that the errors of relative density and shrinkage is below 5% and 2%. Grain growth trend was also basically consistent with the simulation results. After that, the above numerical simulation method was applied into the prediction of fabricating MgTiO3 filter with complex structure. Therefore, the present work provided a reliable numerical simulation method to predict the densification behavior of MgTiO3 ceramics during the pressureless sintering process, which was helpful to design and fabricate microwave dielectric products.

scholarly journals Internal Stability Evaluation of Soils

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1439
Author(s):  
Qingfeng Feng ◽  
Hao-Che Ho ◽  
Teng Man ◽  
Jiaming Wen ◽  
Yuxin Jie ◽  
...  
Keyword(s):  
Experimental Data ◽  
Grain Size ◽  
Numerical Model ◽  
Internal Stability ◽  
Combined Effects ◽  
Stability Evaluation ◽  
Major Threat ◽  
Satisfactory Performance ◽  
Proposed Model ◽  
Simulation Results

Suffusion constitutes a major threat to the foundation of a dam, and the likelihood of suffusion is always determined by the internal stability of soils. It has been verified that internal stability is closely related to the grain size distribution (GSD) of soils. In this study, a numerical model is developed to simulate the suffusion process. The model takes the combined effects of GSD and porosity (n) into account, as well as Wilcock and Crowe’s theory, which is also adopted to quantify the inception and transport of soils. This proposed model is validated with the experimental data and shows satisfactory performance in simulating the process of suffusion. By analyzing the simulation results of the model, the mechanism is disclosed on how soils with specific GSD behaving internally unstable. Moreover, the internal stability of soils can be evaluated through the model. Results show that it is able to distinguish the internal stability of 30 runs out of 36, indicating a 83.33% of accuracy, which is higher than the traditional GSD-based approaches.

scholarly journals Numerical Study on Crack Propagation by Using Softening Model under Blasting

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Rong Hu ◽  
Zheming Zhu ◽  
Jun Xie ◽  
Dingjun Xiao
Keyword(s):  
Numerical Simulation ◽  
Crack Propagation ◽  
Numerical Study ◽  
Numerical Models ◽  
Incident Angle ◽  
Damage Model ◽  
Maximum Principal Stress ◽  
Stress Criterion ◽  
Proposed Model ◽  
Simulation Results

A mixed failure criterion, which combined the modified maximum principal stress criterion with the damage model of tensile crack softening, was developed to simulate crack propagation of rock under blasting loads. In order to validate the proposed model, a set of blasting models with a crack and a borehole with different incident angles with the crack were established. By using this model, the property of crack propagation was investigated. The linear equation of state (EOS) was used for rock, and the JWL EOS was applied to the explosive. In order to validate the numerical simulation results, experiments by using PMMA (polymethyl methacrylate) with a crack and a borehole were carried out. The charge structure and incident angle of the blasting experimental model were the same as those in the numerical models. The experiment results agree with the numerical simulation results.

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.

A CLASS OF INTERACTING PARTICLE SYSTEMS ON THE INFINITE CYLINDER WITH FLOCKING PHENOMENA

2012 ◽  
Vol 22 (07) ◽  
pp. 1250008 ◽  
Author(s):  
SEUNG-YEAL HA ◽  
MOON-JIN KANG ◽  
CORRADO LATTANZIO ◽  
BRUNO RUBINO
Keyword(s):  
Numerical Simulation ◽  
Interacting Particle Systems ◽  
Sufficient Conditions ◽  
Particle Systems ◽  
Kuramoto Model ◽  
Infinite Cylinder ◽  
Interacting Particle ◽  
Proposed Model ◽  
Simulation Results ◽  
Flocking Motion

We present a class of extended Kuramoto models describing a flocking motion of particles on the infinite cylinder and provide sufficient conditions for the asymptotic formation of locked solutions where the distance between particles remains constant. Our proposed model includes the complex Kuramoto model for synchronization. We also provide several numerical simulation results and compare them with analytical 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.

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