scholarly journals KINETIC EVOLUTION OF A 3D SPHERICAL CRYSTAL WITH MOBILE PARTICLESUSING MONTE CARLO - PART II

Anales AFA ◽  
2020 ◽  
pp. 79-84
Author(s):  
C.L. Di Prinzio ◽  
P.I. Achával ◽  
D. Stoler ◽  
G. Aguirre Varela
Keyword(s):  
Grain Size ◽  
Monte Carlo ◽  
Analytical Solution ◽  
Grain Boundary ◽  
Critical Radius ◽  
Three Dimensional ◽  
Size Evolution ◽  
Computational Data ◽  
Simulation Results ◽  
Spherical Crystal

In this work, the migration of the three-dimensional (3D) spherical crystal in the presence of mobile particles using aMonte Carlo algorithm was studied. Different concentrations of particles (f) and different particles mobilities (Mp)were used. It was found that the grain size reaches a critical radius (Rc) which depends exclusively onf. This dependence can be written as:Rc~f^1/3. The dynamic equation of grain size evolution and its analytical solution were alsofound. The analytical solution successfully fits the simulation results. The particles fraction in the grain boundary wasalso found analytically and it fits with the computational data.

THEORETICAL AND COMPUTER MODELS OF 3-DIMENSIONAL GRAIN BOUNDARY MIGRATION WITH MOBILE PARTICLES

2022 ◽  
Author(s):  
Carlos Leonardo Di Prinzio ◽  
Pastor Ignacio Achaval
Keyword(s):  
Grain Size ◽  
Analytical Solution ◽  
Grain Boundary ◽  
Boundary Migration ◽  
Three Dimensional ◽  
Monte Carlo Algorithm ◽  
3 Dimensional ◽  
Particle Mobility ◽  
Size Evolution ◽  
Computational Data

In this work, the migration of a three-dimensional (3D) spherical crystal in the presence of mobile particles using a Monte Carlo algorithm was studied. Different concentrations of particles (<i>f</i>) and different particle mobility (<i>M<sub>p</sub></i>) were used. It was found that the grain size reaches a critical radius (<i>R<sub>c</sub></i>) which depends exclusively on <i>f</i>. This dependence can be written as: <i>R<sub>c</sub></i>∝<i>f</i><sup>1/3</sup>. The dynamic equation of grain size evolution and its analytical solution were also found. The analytical solution proposed fits successfully the simulation results. The particle fraction in the grain boundary was also found analytically and it fits the computational data.

Influence of grain boundary energy on the grain size evolution in nanocrystalline materials

2009 ◽  
Vol 475 (1-2) ◽  
pp. 893-897 ◽  
Author(s):  
Zheng Chen ◽  
Feng Liu ◽  
Wei Yang ◽  
Haifeng Wang ◽  
Gencang Yang ◽  
...  
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Nanocrystalline Materials ◽  
Boundary Energy ◽  
Grain Boundary Energy ◽  
Size Evolution

scholarly journals The role of grain size evolution in the rheology of ice: implications for reconciling laboratory creep data and the Glen flow law

2021 ◽  
Vol 15 (9) ◽  
pp. 4589-4605
Author(s):  
Mark D. Behn ◽  
David L. Goldsby ◽  
Greg Hirth
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Stress Exponent ◽  
Ice Sheets ◽  
Grain Boundary Sliding ◽  
Dislocation Creep ◽  
Ice Flow ◽  
Size Evolution ◽  
Boundary Sliding ◽  
Flow Law

Abstract. Viscous flow in ice is often described by the Glen flow law – a non-Newtonian, power-law relationship between stress and strain rate with a stress exponent n ∼ 3. The Glen law is attributed to grain-size-insensitive dislocation creep; however, laboratory and field studies demonstrate that deformation in ice can be strongly dependent on grain size. This has led to the hypothesis that at sufficiently low stresses, ice flow is controlled by grain boundary sliding, which explicitly incorporates the grain size dependence of ice rheology. Experimental studies find that neither dislocation creep (n ∼ 4) nor grain boundary sliding (n ∼ 1.8) have stress exponents that match the value of n ∼ 3 in the Glen law. Thus, although the Glen law provides an approximate description of ice flow in glaciers and ice sheets, its functional form is not explained by a single deformation mechanism. Here we seek to understand the origin of the n ∼ 3 dependence of the Glen law by using the “wattmeter” to model grain size evolution in ice. The wattmeter posits that grain size is controlled by a balance between the mechanical work required for grain growth and dynamic grain size reduction. Using the wattmeter, we calculate grain size evolution in two end-member cases: (1) a 1-D shear zone and (2) as a function of depth within an ice sheet. Calculated grain sizes match both laboratory data and ice core observations for the interior of ice sheets. Finally, we show that variations in grain size with deformation conditions result in an effective stress exponent intermediate between grain boundary sliding and dislocation creep, which is consistent with a value of n = 3 ± 0.5 over the range of strain rates found in most natural systems.

An algorithm for smoothing three-dimensional Monte Carlo ion implantation simulation results

2004 ◽  
Vol 66 (2-3) ◽  
pp. 219-230 ◽  
Author(s):  
Clemens Heitzinger ◽  
Andreas Hössinger ◽  
Siegfried Selberherr
Keyword(s):  
Monte Carlo ◽  
Ion Implantation ◽  
Three Dimensional ◽  
Simulation Results

Monte-Carlo Simulation of Goss Abnormal Grain Growth in Fe-3%Si Steel by Sub-Boundary Enhanced Solid-State Wetting

2012 ◽  
Vol 715-716 ◽  
pp. 146-151
Author(s):  
K.J. Ko ◽  
A.D. Rollett ◽  
N.M. Hwang
Keyword(s):  
Monte Carlo ◽  
Solid State ◽  
Grain Boundary ◽  
Grain Growth ◽  
Boundary Energy ◽  
Three Dimensional ◽  
Abnormal Grain Growth ◽  
Grain Boundary Energy ◽  
Simulation Based ◽  
Mc Simulation

The selective abnormal grain growth (AGG) of Goss grains in Fe-3%Si steel was investigated using a parallel Monte-Carlo (MC) simulation based on the new concept of sub-boundary enhanced solid-state wetting. Goss grains with low angle sub-boundaries will induce solid-state wetting against matrix grains with a moderate variation in grain boundary energy. Three-dimensional MC simulations of microstructure evolution with textures and grain boundary distributions matched to experimental data is using in this study.

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.

Modelling of Grain Boundary Stability of Materials under Severe Plastic Deformation and Experimental Verification

2010 ◽  
Vol 638-642 ◽  
pp. 2724-2729
Author(s):  
Yoshiyuki Saito ◽  
Chitoshi Masuda
Keyword(s):  
Monte Carlo ◽  
Grain Boundary ◽  
Computer Simulations ◽  
Phase Field ◽  
Field Methods ◽  
Simulation Results ◽  
Boundary Stability ◽  
Textured Materials ◽  
Phase Field Methods ◽  
Good Agreement

Thermodynamic stability of Grain boundary in materials under severe plastic deformation was simulated by the Monte Carlo and the phase field methods. Computer simulations were performed on 3-dimensional textured materials. The Monte Carlo simulation results were qualitatively in good agreement with those by the phase field model. The classification of the solution of differential equations based on the mean-field Hillert model describing temporal evolution of the scaled grain size distribution function was in good agreement with those given by the Computer simulations. The ARB experiments were performed for pure Al and Al alloys-sheets in order to validate the computer simulation results concerning the grain boundary stability of textured materials. With use of the Monte Carlo and the phase field methods. Effect of grain boundary mobilises and interface energy given by the computer simulations.

Study on Grain Topology with Potts Model Monte Carlo Simulation

2014 ◽  
Vol 926-930 ◽  
pp. 1538-1541
Author(s):  
Hao Wang ◽  
Guo Quan Liu
Keyword(s):  
Experimental Data ◽  
Monte Carlo ◽  
Potts Model ◽  
Three Dimensional ◽  
Wide Range ◽  
The Mean ◽  
Simulation Results ◽  
Number Of Faces ◽  
Grain Topology ◽  
Range Of Values

Three-dimensional normal grain growth has been simulated in scale 300×300×300 using the generally accepted Potts model Monte Carlo method. The studies of the topology of grains indicate that the mean number of faces in the grain network <f>=13.91 is similar to other simulation results, but higher than most of the experimental data which containing a wide range of values, i.e., <f>=11.16~13.93. The three-dimensional AboavWeaire law and Liu-Yu law are observed to hold, but the fit coefficient is different from the theory models.

scholarly journals Study on size of laser entrance hole shield for ignition octahedral spherical hohlraums

2015 ◽  
Vol 33 (4) ◽  
pp. 731-739 ◽  
Author(s):  
Shu Li ◽  
Ke Lan ◽  
Jie Liu
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Analytical Model ◽  
Critical Radius ◽  
Coupling Efficiency ◽  
Three Dimensional ◽  
Main Pulse ◽  
Laser Spot ◽  
Entrance Hole ◽  
Target Design

AbstractIn this paper, the influences of laser entrance hole shields on capsule symmetry and coupling efficiency of an ignition octahedral spherical hohlraum are studied using analytical model and three-dimensional Monte-Carlo simulations. As a result, there are two critical shield radii at which the capsule asymmetry tends to minimum, and the coupling efficiency from hohlraum to capsule reaches its maximum when the shield size is taken around the second critical radius. For the ignition octahedral hohlraums used in our study, the first critical radius is 0.625 mm with a capsule asymmetry of 0.24%, and the second is 0.86 mm with 0.26%, and the asymmetry is smaller than 0.58% for shields’ radius in the range of 0.44 and 0.88 mm, which therefore leaves much flexibility in the shield radius design even the shields have an expansion under radiation ablation. The initial shield radius can be taken around the first critical radius in the ignition target design, not only to have a minimum initial capsule radiation asymmetry, but also to get a minimum asymmetry and highest coupling efficiency during the main pulse of drive. Finally, the relative flux of laser spot, wall and shields is 2.2:1:0.6 for our ignition octahedral spherical hohlraum model from the Monte-Carlo simulations.

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