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.

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.

Macro-Micro Modeling and Simulation of Solidification Kinetics of Pb-Sn Alloys

2006 ◽  
Vol 509 ◽  
pp. 171-176
Author(s):  
L. López ◽  
H. Cruz ◽  
B. Campillo ◽  
Carlos González-Rivera
Keyword(s):  
Heat Transfer ◽  
Solidification Rate ◽  
Primary Phase ◽  
Experimental Results ◽  
Eutectic Solidification ◽  
Cooling Curves ◽  
Solidification Kinetics ◽  
Eutectic Morphology ◽  
Micro Modeling ◽  
Kinetics Of

The purpose of this work is to explore the effect of the presence of two different primary phases on the microstructure and solidification kinetics of Pb-Sn alloys. The experimental results have been compared with predictions obtained from the Newton Thermal Analysis of cooling curves generated by a conventional heat transfer-solidification kinetics model. Three Pb-Sn alloys have been considered in this work in order to explore the solidification characteristics of the eutectic in hypoeutectic, hypereutectic and eutectic compositions. Experimental results indicate that the Pb-Sn eutectic morphology and the solidification rate depend on the nature of the pre-existent primary phase during eutectic solidification. From the observed discrepancies between experimental and simulated results it is concluded that further improvements are needed to simulate the solidification kinetics of eutectic microconstituents in the presence of pre-existing primary phases.

Squeal and Thermal Analysis of Automobile Disc Brake Rotors

2015 ◽  
Vol 764-765 ◽  
pp. 369-373
Author(s):  
Wei Hsin Gau ◽  
Kun Nan Chen ◽  
Chin Yuan Hung
Keyword(s):  
Heat Transfer ◽  
Thermal Analysis ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Cast Iron ◽  
Cfd Simulation ◽  
Transfer Coefficients ◽  
Element Analysis ◽  
Heat Transfer Coefficients ◽  
Brake Rotors

The brakes of an automobile are among the most critical components regarding the safety features, and disc brakes are the most common type used in passenger vehicles. In this research, the squeal phenomena of a swirl-vent brake rotor and the thermal analysis of two straight-vent brake rotors, made of cast-iron and aluminum-alloy, are investigated. For the squeal analysis, finite element models are created and analyzed using a prestressed modal analysis with complex eigen-solutions. For the thermal analysis, heat transfer coefficients on the surfaces of a rotor as functions of time are first estimated by CFD simulation, and then imported to a thermal analysis program as the boundary condition. Finally, the temperature distribution of the rotor can be calculated by finite element analysis. The simulation results show that vortices will arise in the vented passages of straight-vent rotors, which means less heat carried away and lower heat transfer coefficients. The swirl-vent brake design is clearly better for thermal ventilation. Furthermore, under the same condition, aluminum-alloy rotors exhibit more uniform temperature distributions with smaller temperature gradients than cast-iron rotors do.

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.

Numerical Simulation on the Temperature Field of Steel 1045 Quenched by Different Hardening Media

2013 ◽  
Vol 444-445 ◽  
pp. 1222-1228
Author(s):  
Jian Bin Xie ◽  
Chang Chang Wu ◽  
Jing Fan ◽  
Miao Fu ◽  
Deng Feng Hu
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Temperature Field ◽  
Temperature Fields ◽  
Cooling Curves ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Heat Transfer Theory ◽  
Quenching Process ◽  
Estimate Method

Based on the experimental measured cooling curves and the boiling heat transfer theory, the inverse problem of nonlinear heat conduct equation for Steel 1045 quenched by different hardening media was established by functional analysis and finite element method, and the surface heat-transfer coefficients in continuous cooling during quenching were calculated by nonlinear estimate method. Then the constitutive model of Steel 1045 during quenching was established subsequently. Finally, the temperature field of Steel 1045 cylinder quenched by different hardening media was simulated by Finite Element Methods (FEM). Results show that the calculated temperature fields agree with the practical quenching process.

Thermal Analysis of Mixed Electroosmotic and Pressure Driven Flows in Two-Dimensional Straight Microchannels

Volume 4 ◽  
2004 ◽  
Author(s):  
Keisuke Horiuchi ◽  
Prashanta Dutta
Keyword(s):  
Heat Transfer ◽  
Thermal Analysis ◽  
Pressure Gradient ◽  
Two Dimensional ◽  
Transfer Coefficients ◽  
Nusselt Numbers ◽  
Micro Channels ◽  
Micro Flows ◽  
Pressure Driven Flow ◽  
Pressure Driven

Analytical solution for the temperature distributions, heat transfer coefficients, and Nusselt numbers of steady electroosmotic flows with an arbitrary pressure gradient are obtained for two-dimensional straight micro-channels. The thermal analysis considers interaction among inertial, diffusive and Joule heating terms in order to obtain the thermally developing behavior of mixed electroosmotic and pressure driven flows. In mixed flow cases, the governing equation for energy is not separable in general. Therefore, we introduced a new method that considers the extended Graetz problem. Heat transfer characteristics are presented for low Reynolds number micro-flows where the viscous and electric field terms are very dominant. Analytical results show that the heat transfer coefficient of mixed-electroosmotic and pressure driven flow is smaller than that of pure electroosmotic flow. For the parameter range studied here (Re<0.7), the fully developed Nusselt number is independent of the thermal Peclet number and pressure gradient. Moreover, in mixed electroosmotic and pressure driven flows, the thermal entrance length increases with the imposed pressure gradient.

Effect of Latent Heat Related to Solidification Kinetics on Heat Transfer during Solidification of Al Alloy

2014 ◽  
Vol 884-885 ◽  
pp. 273-276
Author(s):  
Seok Jae Lee
Keyword(s):  
Heat Transfer ◽  
Latent Heat ◽  
Temperature Compensation ◽  
Solid Phase ◽  
A356 Alloy ◽  
Cooling Curve ◽  
Al Alloy ◽  
Cooling Curves ◽  
Solidification Kinetics ◽  
Heat Transfer Simulation

The effect of the latent heat related to the rate of the solidification kinetics during solidification was investigated by using the heat transfer simulation. The latent heat was generated proportional to the amount of the fraction of transformed solid phase and directly affected the temperature compensation during solidification. The importance of the solidification kinetics was discussed by comparing cooling curves calculated using different solidification kinetics with experimentally measured cooling curve of A356 alloy.

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