Numerical Processing of Cooling Curves to Obtain Growth Parameters During Eutectic Solidification

2012 ◽  
Vol 1373 ◽  
Author(s):  
M. Morua ◽  
E. Peña ◽  
R. Aparicio ◽  
M. Ramirez-Argaez ◽  
C. Gonzalez-Rivera
Keyword(s):  
Kinetic Parameters ◽  
Grain Growth ◽  
Growth Parameters ◽  
Mechanistic Model ◽  
Eutectic Solidification ◽  
Exponential Dependence ◽  
Cooling Curves ◽  
Numerical Processing ◽  
Fourier Thermal Analysis ◽  
Grain Growth Kinetics

ABSTRACTIn this work a methodology to measure kinetic parameters to describe grain growth during equiaxed eutectic solidification is proposed. This methodology includes the numerical processing of two cooling curves and requires input data concerning the number of grains per unit volume. In addition, free grain growth before impingement and an exponential dependence of the grain growth rate on undercooling are assumed. The evolution of solid fraction of the sample as a function of time is obtained by applying the Fourier thermal analysis (FTA) method. Information collected is processed numerically in order to find numerical values for the pre-exponential and exponential parameters that characterize the grain growth kinetics as a function of undercooling. To validate this methodology a mechanistic model that simulates the cooling and solidification of eutectic Al-Si alloy in a sand mold is used. The results suggest that this methodology can be used to measure the kinetic parameters of equiaxed growth from the numerical processing of cooling curves and grain density data.

On the characterization of eutectic grain growth during solidification

2012 ◽  
Vol 1485 ◽  
pp. 161-166
Author(s):  
M. Morua ◽  
M. Ramirez-Argaez ◽  
C. Gonzalez-Rivera
Keyword(s):  
Heat Transfer ◽  
Cast Iron ◽  
Kinetic Parameters ◽  
Grain Growth ◽  
Eutectic Solidification ◽  
Cooling Curves ◽  
Density Data ◽  
Solidification Kinetics ◽  
Grain Growth Kinetics

ABSTRACTThe purpose of this work is to compare the results obtained from three methodologies intended to estimate kinetic parameters describing quantitatively the grain growth during equiaxed eutectic solidification in order to identify the best procedure to characterize grain growth kinetics. A heat transfer / solidification kinetics model is implemented to simulate the cooling and solidification of eutectic Al-Si and eutectic cast iron in sand molds. Using simulated cooling curves and volume grain density data generated by the model, the three methods are applied to obtain their predicted grain growth coefficients. The predicted results are compared with the grain growth coefficients used in the model. The outcome of this work suggests that two of the three methods under study represent the best option to obtain the kinetic parameters of equiaxed growth during eutectic solidification.

Thermal and Kinetic Analysis of the solidification of a near eutectic Al-Cu Alloy

2014 ◽  
Vol 1611 ◽  
pp. 105-110
Author(s):  
M. Morua ◽  
M. Ramirez-Argaez ◽  
C. Gonzalez-Rivera
Keyword(s):  
Heat Transfer ◽  
Thermal Analysis ◽  
Kinetic Analysis ◽  
Eutectic Growth ◽  
Eutectic Solidification ◽  
Cooling Curves ◽  
Transfer Coefficients ◽  
Fourier Thermal Analysis ◽  
Cu Alloy ◽  
Solidification Kinetics

ABSTRACTIn this work the thermal and kinetic analysis of the cooling and solidification of a near eutectic Al-Cu alloy is performed using inverse thermal and solidification kinetics analysis. The Fourier thermal analysis is applied to experimental cooling curves to obtain data on solid fraction evolution and latent heat of solidification. Inverse thermal analysis is applied to calculate the global heat transfer coefficients that allow correct simulation of the cooling of experimental probes. The free growth method is used to obtain the eutectic growth coefficients. All the obtained parameters are feed into a heat transfer-solidification kinetics model to validate the methodology and results generated from this work. It is found a relatively good agreement between experimental and predicted cooling curves which suggest that this methodology could be used to generate useful information needed to simulate eutectic solidification.

β Grain Growth Kinetics of a New Metastable β Titanium Alloy

2013 ◽  
Vol 747-748 ◽  
pp. 844-849 ◽  
Author(s):  
Yue Fei ◽  
Xin Nan Wang ◽  
Zhi Shou Zhu ◽  
Jun Li ◽  
Guo Qiang Shang ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Grain Growth ◽  
Kinetic Equations ◽  
Type Equation ◽  
Growth Exponent ◽  
Solution Treated ◽  
Growth Activation ◽  
Grain Growth Kinetics ◽  
Kinetics Of ◽  
Strength And Ductility

Ti-Mo-Nb-Cr-Al-Fe-Si alloy is a new metastable β titanium alloy with excellent combination of strength and ductility. The β grain-growth exponent and the activation energies for β grain growth for the investigated alloy at specified temperature were computed by the kinetic equations and the Arrhenius-type equation. The rate of β grain growth decreases with elongating solution treated time and increases with the increasing solution-treated temperature. The β grain-growth exponents, n, are 0.461, 0.464 and 0.469 at 1113, 1133 and 1153K, respectively. The β grain growth activation energy is determined to be 274 KJ/mol.

scholarly journals Quantitative Characterization of Geotrichum candidum Growth in Milk

2021 ◽  
Vol 11 (10) ◽  
pp. 4619
Author(s):  
Petra Šipošová ◽  
Martina Koňuchová ◽  
Ľubomír Valík ◽  
Monika Trebichavská ◽  
Alžbeta Medveďová
Keyword(s):  
Growth Parameters ◽  
Mechanistic Model ◽  
Geotrichum Candidum ◽  
Activity Level ◽  
Effect Of Temperature ◽  
Operational Parameters ◽  
Quantitative Characterization ◽  
Essential Knowledge ◽  
Cardinal Temperatures

The study of microbial growth in relation to food environments provides essential knowledge for food quality control. With respect to its significance in the dairy industry, the growth of Geotrichum candidum isolate J in milk without and with 1% NaCl was investigated under isothermal conditions ranging from 6 to 37 °C. The mechanistic model by Baranyi and Roberts was used to fit the fungal counts over time and to estimate the growth parameters of the isolate. The effect of temperature on the growth of G. candidum in milk was modelled with the cardinal models, and the cardinal temperatures were calculated as Tmin = −3.8–0.0 °C, Topt = 28.0–34.6 °C, and Tmax = 35.2–37.2 °C. The growth of G. candidum J was slightly faster in milk with 1% NaCl and in temperature regions under 21 °C. However, in a temperature range that was close to the optimum, its growth was slightly inhibited by the lowered water activity level. The present study provides useful cultivation data for understanding the behaviour of G. candidum in milk and can serve as an effective tool for assessing the risk of fungal spoilage, predicting the shelf life of dairy products, or assessing the optimal conditions for its growth in relation to the operational parameters in dairy practices.

Grain growth kinetics, microstructure and magnetic properties of mechanically activated Nd1−xCaxMnO3±δ manganites

2021 ◽  
Vol 864 ◽  
pp. 158816
Author(s):  
Galina Kozhina ◽  
Valentin Mitrofanov ◽  
Olga Fedorova ◽  
Andrey Fetisov ◽  
Aidar Murzakaev ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Grain Growth ◽  
Growth Kinetics ◽  
Grain Growth Kinetics ◽  
Microstructure And Magnetic Properties
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