Ivaldo L. Ferreira

Recently, a model was proposed to predict cv as a function of temperature from the absolute zero to the melting temperature applied. This solution was based on critical grain nucleation to determine the volume, which contains the total number of modes for a particular equilibrium and non-equilibrium state to calculate the density of state (DoS), which is strongly dependent on the nucleus radius for both pure element and compound. Electronic and rotational energies were regarded for both elements and compounds in this formulation. The anomalies associated with cv can be easily considered in terms of their entropies, independent of their nature, as a local change in the DoS. Comparisons of cv for elements and compounds are performed against Thermodynamics software simulations and experimental data.

10.6084/m9.figshare.14306007

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APLICAÇÃO DA TERMODINÂMICA COMPUTACIONAL PARA DETERMINAÇÃO DE PROPRIEDADES TERMOFÍSICAS EM FUNÇÃO DA TEMPERATURA PARA A LIGA Al-6%pCu-1%pSi

Fabiana Cristina Nascimento M. C. C. PARESQUE L. F. LA SALVIA Ivaldo L. Ferreira

As ligas de alumínio baseadas no ternário Al-Cu-Si (ASTM 231.1) possuem considerável importância tecnológica devido a sua baixa densidade, relativamente baixo ponto de fusão e boa resistência mecânica específica comparadas ao aço. Essas ligas são empregadas na indústria automobilística e aeroespacial. No entanto, apesar de sua importância tecnológica, suas propriedades termofísicas, úteis aos processos de fabricação, que envolvam transferência de calor, como, soldagem, fundição e tratamentos termomecânicos, são escassas na literatura. Propõe-se nesse trabalho, um levantamento de algumas destas propriedades, como, massa especifica em função da temperatura, entalpia de transformação e calores específicos para a liga Al-6%pCu-1%pSi, através da termodinâmica computacional. Os resultados simulados para massa específica em função da temperatura com relação aos resultados experimentais obtidos na literatura para as ligas de alumínio A319 e 7075 validam de forma satisfatória o modelo proposto.

Non-blocking I/O

LIGA

10.5151/chemeng-cobeq2014-0260-26294-175580

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Cellular growth during transient directional solidification of Pb–Sb alloys

Journal of Alloys and Compounds (2006)

Daniel Monteiro Rosa José Eduardo Spinelli Ivaldo L. Ferreira Amauri Garcia

Directional solidification

Transient (computer programming)

10.1016/j.jallcom.2005.12.011

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Citations (40)

On the continuous mechanics first- and second-order formulations for non-equilibrium nucleation: Derivation and applications

Research Square (Research Square) (2023)

Ivaldo L. Ferreira Antônio Luciano Seabra Moreira

Abstract Nucleation and growth are phenomena that can be applied to several fields of science and technology. On the other hand, nucleation depends on the cooling rate, dislocating the equilibrium, as surface energy depends on the created and deformed surface area. The crystalline/glassy transition limit dependence on the thermal gradient is also analyzed. In this paper, under the continuum mechanics, first- and second-order non-equilibrium nucleation formulation models are derived, and a phase-change moving interface is considering the thermal field. Nucleation important variables will be plotted against the cooling rate for several nucleation angles. It will be coupled with a theoretical model for the molar-specific heat capacity of solids to analyze its dependence on nucleation kinetics.

Classical nucleation theory

Statistical Mechanics

10.21203/rs.3.rs-2512079/v1

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On an expression for the growth of secondary dendrite arm spacing during non-equilibrium solidification of multicomponent alloys: Validation against ternary aluminum-based alloys

Journal of Manufacturing Processes (2018)

Ivaldo L. Ferreira Antônio Luciano Seabra Moreira Julio A.S. Aviz Thiago A. Costa Otávio L. Rocha

Dendrite (mathematics)

Supercooling

Directional solidification

10.1016/j.jmapro.2018.08.010