Monte-Carlo Modeling of Recrystallization Kinetics of Cold-Rolled Titanium

2010 ◽  
Vol 654-656 ◽  
pp. 1486-1491 ◽  
Author(s):  
Y.B. Chun ◽  
S. Lee Semiatin ◽  
Sun Keun Hwang
Keyword(s):  
Monte Carlo ◽  
Heterogeneous Nucleation ◽  
Negative Deviation ◽  
Stored Energy ◽  
High Deformation ◽  
Recrystallization Kinetics ◽  
Cold Rolled ◽  
Log Normal ◽  
Kinetics Of ◽  
Log Normal Distribution

The recrystallization behavior of cold-rolled, commercial-purity titanium was studied experimentally and with Monte-Carlo (MC) modeling. Utilization of EBSD-OIM as input for MC modeling resulted in realistic predictions of recrystallization kinetics, microstructure and texture, which were in good agreement with experimental results. MC modeling of recrystallization kinetics predicted that the non-uniform stored energy distribution, heterogeneous nucleation of recrystallization and recovery in combination leads to a negative deviation from linear JMAK kinetics. It was found that concurrent recovery that takes place during recrystallization is an important process that controls both the overall recrystallization kinetics and the deviation of linear JMAK kinetics. On the other hand, the non-uniformly distributed stored energy itself has little effect on the negative deviation from JMAK kinetics but intensifies the deviation when heterogeneous nucleation is combined. Modeling results also revealed that heterogeneous nucleation of recrystallized grains and their early impingement in local areas of high deformation are essential for producing a log-normal distribution of grain size and a typical recrystallization texture of rolled titanium.

Precipitation and Recrystallization in an Al-Mg-Sc Alloy

2006 ◽  
Vol 519-521 ◽  
pp. 1647-1652 ◽  
Author(s):  
R. Roumina ◽  
Chad W. Sinclair ◽  
F. Fazeli
Keyword(s):  
Microstructural Evolution ◽  
Annealing Temperature ◽  
Microstructural Stability ◽  
Rolled Material ◽  
Recrystallization Kinetics ◽  
Cold Rolled ◽  
Kinetics Of Precipitation ◽  
Kinetics Of ◽  
Relative Kinetics

The addition of scandium severely retards the recrystallization of Al-Sc alloys when it is present in the form of fine Al3Sc precipitates. Though many studies have focused on the role of Al3Sc in the deformation and recrystallization of pre-aged or hot deformed Al-Sc alloys, recent studies on the annealing response of solutionized and cold rolled material have shown various possibilities for microstructural stability depending on the relative kinetics of precipitation and recrystallization. In this study, the microstructural evolution of solutionized and cold rolled Al- 2.9wt%Mg-0.16wt%Sc has been followed in order to evaluate the role of imposed strain and annealing temperature on the recrystallization kinetics.

Monte Carlo Modelling of Recrystallization Process in Cold Rolled IF-Ti Steel

2004 ◽  
Vol 467-470 ◽  
pp. 665-670
Author(s):  
Amel Samet-Meziou ◽  
Ph. Gerber ◽  
Jacek Tarasiuk ◽  
Thierry Baudin ◽  
Richard Penelle
Keyword(s):  
Monte Carlo ◽  
Texture Evolution ◽  
Recrystallization Process ◽  
Stored Energy ◽  
Nucleation Mechanisms ◽  
Deformation Amount ◽  
Complete Set ◽  
High Reduction ◽  
Cold Rolled ◽  
Electron Back Scattered Diffraction

Recently, some authors have used the Monte Carlo modelling using complete set of experimental data to get a better correlation between experimental observations and calculations concerning recrystallization process [1, 2]. Simulations using Monte Carlo technique have been performed these last years for IF-Ti steels in order to predict the microstructure and the texture evolution after high reduction amounts by cold rolling [3, 4]. On the contrary, in the present work, this evolution is simulated in an IF-Ti steel cold rolled after low deformation amount (reduction amount R = 40 %). Microstructure is characterized by Electron Back-Scattered Diffraction and introduced in the model. The quality index of the Kikuchi patterns (EBSD data) is used to qualitatively evaluate the stored energy for each grain. Different hypothesis of nucleation mechanisms have been introduced into the model. It has been shown that the better recrystallization texture correlation between experiment and simulation is obtained by taking into account the nucleation in the low stored energy sites and highly misorientation regions. Finally a simulation issue was compared with EBSD and TEM experimental results: microstructure, recrystallization kinetics and Avrami coefficients values.

A Bayesian Monte Carlo Markov Chain Method for Loss Models and Risk Measure Assessments

2009 ◽  
Vol 12 (03) ◽  
pp. 529-543
Author(s):  
Ling Hu ◽  
Yating Yang
Keyword(s):  
Monte Carlo ◽  
Markov Chain ◽  
Normal Distribution ◽  
Risk Measure ◽  
Markov Chain Method ◽  
Flood Loss ◽  
Bayesian Monte Carlo ◽  
Loss Models ◽  
Log Normal ◽  
Log Normal Distribution

Natural disasters are also known as catastrophes with low frequency but high damages. Typhoons and floods are the major catastrophes which lead to gargantuan losses in Asia. Once a disaster occurs, a broad region will be affected and this will result in huge social loss. If issuers or governments use the wrong loss models or risk measure indexes to price the related insurance products, they will get an inaccurate price and thus be insolvent to the claims. Previous researches often use a Log-Normal distribution to model a catastrophic loss. This is not appropriate since the characteristics of a loss distribution have some empirical facts, including the positive skewness and the heavy-tailed properties. Recently, some studies (McNeil and Frey, 2000; Rootzen and Tajvidi, 2000; Thuring et al., 2008) also point out that using Log-Normal distribution to model a characteristic loss is not suitable. Therefore, we build a typhoon and flood loss model with higher order moments and estimate the parameters through a Bayesian Monte Carlo Markov Chain method. According to the Kolmogorov-Smirnov test, we find that the Pareto distribution is more adaptive for modeling the loss of typhoon and flood. Further, we evaluate different kinds of risk measure indexes through simulating and numerical analysis. It gives the beacon to issuers or governments when they want to issue the insurance products about typhoon and flood loss.

Coupling of Local Texture and Microstructure Evolution during Restoration Processes in Aluminum Deformed to Large Strains

2013 ◽  
Vol 753 ◽  
pp. 251-256
Author(s):  
Niels Hansen ◽  
Tian Bo Yu ◽  
Oleg V. Mishin ◽  
Xiao Xu Huang
Keyword(s):  
Rolling Texture ◽  
Large Strains ◽  
Boundary Mobility ◽  
Stored Energy ◽  
Local Texture ◽  
Deformed State ◽  
Cold Rolled ◽  
The Individual ◽  
Kinetics Of

The coupling between local texture and microstructure is analyzed during restoration processes in aluminum cold-rolled to high and ultrahigh strains. The deformed microstructure is composed of lamellae with orientations of rolling texture components that occupy different volume fractions and vary in the spatial distribution. The individual lamellae are separated by low and high angle boundaries and significant local differences are produced in the deformed microstructure both in terms of the stored energy and boundary mobility. These differences influence recovery and recrystallization processes, resulting in significant local variations in mechanisms and kinetics of these processes. The observations suggest that the characterization of the local texture and microstructure both in the deformed state and after annealing is important in order to underpin the analysis of recovery and recrystallization on the sample scale.

SOĞUK HADDELENMİŞ AA3105 VE AA5005 LEVHALARIN DSC ANALİZİ İLE YENİDEN KRİSTALLENME KİNETİĞİ

2021 ◽  
Vol 8 (17) ◽  
pp. 80-85
Author(s):  
Atae RAOUGUI ◽  
Ion GRECU ◽  
Volkan Murat YILMAZ ◽  
Kenan YILDIZ
Keyword(s):  
Differential Scanning Calorimetry ◽  
Aluminum Alloy ◽  
Activation Energies ◽  
Isothermal Kinetics ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Recrystallization Kinetics ◽  
Model Free ◽  
Cold Rolled ◽  
Kinetics Of

In this study, the non-isothermal recrystallization kinetics of cold rolled AA3105 and AA5005 aluminum alloy sheets obtained from ASAŞ Aluminum located in Akyazı-Sakarya was studied by using differential scanning calorimetry (DSC). The non – isothermal kinetics was performed by using Kissenger, Boswell, Ozawa and Starink methods known as model – free methods. The recrystallization temperatures on DSC graphics at different heating rates (β) were deduced and the activation energies were calculated from the slopes from Y – 1/T diagrams. Y is ln(β/T2) for Kissenger, ln(β/T) for Boswell, ln(β) for Ozawa and ln(β/T1.92) for Starink. The results showed that the activation energies of recrystallization are in the range of 194 – 206 kJ/mol for cold rolled AA5005 sheet and in the range of 235 – 257 kJ/mol for cold rolled AA3105 sheet, according to four non-isothermal kinetics model.

scholarly journals Effects of Widening during Rolling on the Subsequent Recrystallization Kinetics of Copper

2013 ◽  
Vol 753 ◽  
pp. 285-288
Author(s):  
Feng Xiang Lin ◽  
Torben Leffers ◽  
Wolfgang Pantleon ◽  
Dorte Juul Jensen
Keyword(s):  
Recrystallization Texture ◽  
Electron Backscatter Diffraction ◽  
Cube Texture ◽  
Recrystallization Process ◽  
Recrystallization Kinetics ◽  
Two Samples ◽  
Electron Backscatter ◽  
Cold Rolled ◽  
Backscatter Diffraction ◽  
Kinetics Of

Recrystallization kinetics in copper cold-rolled to 90% reduction with and without significant widening was investigated by electron backscatter diffraction. It was found that the recrystallization process was slightly retarded and the development of cube recrystallization texture was largely inhibited in the widening sample. Cube grains were observed to have a growth advantage by a factor of 2 in the non-widening sample, while this growth advantage was not observed in the widening sample. The recrystallization kinetics and the development of cube texture in the two samples are discussed.

Mixed Vertex - Monte Carlo Model of Recrystallization

2007 ◽  
Vol 558-559 ◽  
pp. 1151-1156
Author(s):  
Krystian Piękoś ◽  
Jacek Tarasiuk ◽  
Krzysztof Wierzbanowski ◽  
Brigitte Bacroix
Keyword(s):  
Monte Carlo ◽  
Boundary Energy ◽  
Monte Carlo Model ◽  
Monte Carlo Algorithm ◽  
Recrystallization Process ◽  
Vertex Model ◽  
Stored Energy ◽  
Boltzmann Factor ◽  
Stochastic Nature ◽  
Cold Rolled

The generalized deterministic vertex model was successfully used to study the recrystallization process and the corresponding results were published elsewhere [1]. In its classical form the vertex model has analytical formulation, basing on the total energy (i.e. boundary energy and stored energy) minimization. A change of grain boundary configuration in classical vertex model is found by the calculation of vertex velocities. Consequently, a global and complex system of equations has to be solved in each step. In order to simplify calculations and to handle the problem in a more flexible way, the statistical model was proposed. Typical elements of Monte Carlo algorithm were incorporated into the vertex model: a random (and small) modification of microstructure is accepted with the probability proportional to Boltzmann factor. This approach is closer to the stochastic nature of recrystallization process. The model was used to study the recrystallization of 70% and 90% cold rolled polycrystalline copper. It predicts correctly recrystallization textures for high and low strains.

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