Papers by Doru M Stefanescu
Atomic Scale Phenomena: Nucleation and Growth
Springer eBooks, 2002
Semisolid Processing
Springer eBooks, 2015
Macro-energy transport
Springer eBooks, Sep 18, 2008
There are three forms of energy transport: conduction (diffusive transport), convection (heat tra... more There are three forms of energy transport: conduction (diffusive transport), convection (heat transmitted by the mechanical motion of the fluid) and/or radiation (through space). All three are active during solidification of a casting. Energy diffusion and convection occurs within the casting, at the metal/mold interface, and within the mold. Energy is transported by radiation from the mold to its environment, which is typically the air.
Macro-Modeling of Solidification. Numerical Approximation Methods
Springer eBooks, 2002
From the analysis of solidification based on the energy transport equation presented in the previ... more From the analysis of solidification based on the energy transport equation presented in the previous section, it was seen that analytical solutions of this equation are not always available. Significant simplifying assumptions must be used, assumptions that are many times debilitating to the point that the solution is of little engineering interest. Fortunately, with the development of numerical methods and their application to the solution of partial differential equations, the most complicated equations can be solved numerically. Numerical solutions rely on replacing the continuous information contained in the exact solution of the differential equation with discrete values. Discretization equations are derived from the governing differential equation.
Surface Quality and Mold-Metal Interface Interaction
Momentum Mass Transport at the Macroscale
During casting solidification, significant flow of the molten metal will affect the local composi... more During casting solidification, significant flow of the molten metal will affect the local composition. The driving forces for fluid flow can be internal or external. The internal sources of fluid flow include shrinkage (solidification contraction) flow, natural convection, capillary forces, formation of gas bubbles, and deformation of solid phases because of thermal stress and static pressure. The external driving forces may include centrifugal and/or electromagnetic forces.
Microshrinkage
Springer eBooks, 2015
A History of Cast Iron
ASM International eBooks, 2017
Experiments on the growth of Y-Ba-Cu oxide single crystals
Importance of the Lanthanum/Rare Earth Ratio in the Production of Compacted Graphite Cast Irons
Diffusive Energy Transport at the Macroscale
Springer eBooks, 2015
Energy transport from the casting to the environment is ultimately responsible for solidification... more Energy transport from the casting to the environment is ultimately responsible for solidification. There are three forms of energy transport: conduction (diffusive transport), convection (heat transmitted by the mechanical motion of the fluid), and/or radiation (through space). All three are active during solidification of a casting. Energy diffusion and convection occurs within the casting, at the metal/mold interface, and within the mold. Energy is transported by radiation from the mold to its environment, which is typically the air.
Atomic scale phenomena - Nucelation and growth
Springer eBooks, Sep 18, 2008
Solidification is the result of the formation of stable clusters of solid in the liquid (nucleati... more Solidification is the result of the formation of stable clusters of solid in the liquid (nucleation), followed by their growth. These are phenomena occurring at the atomic scale (nano meter) level. The present understanding of the beginning of formation of solid crystals from their liquid is based on the classical theory of homogeneous nucleation. This theory uses macroscopic concepts and classic thermodynamics to describe the appearance of the first microscopic crystals in the melt.
Modeling of equiaxed primary and eutectic solidification
Physical Properties of Cast Irons
ASM International eBooks, 2017
Thermodynamic Concepts—Equilibrium and Nonequilibrium During Solidification
Springer eBooks, 2015
Thermodynamics is a useful tool for the analysis of solidification. It is used to evaluate alloy ... more Thermodynamics is a useful tool for the analysis of solidification. It is used to evaluate alloy phase constitution, the solidification path, basic alloy properties such as partition coefficients , slopes of liquidus, and solidus phase boundaries.
Methodologies for and Performance of Macro Transport-Transformation Kinetics Modeling of Cast Iron
Advanced Materials Research, Oct 1, 1997
Macro-mass transport
Springer eBooks, Oct 8, 2008
The mechanisms of mass transport include species diffusion and momentum transfer (fluid convectio... more The mechanisms of mass transport include species diffusion and momentum transfer (fluid convection). The effects of these mechanisms on casting solidification will be discussed in this chapter.
A Succinct History of Metalcasting Knowledge
International Journal of Metalcasting, Feb 10, 2023
Fundamentals of Transport Phenomena as Applied to Solidification Processing
Springer eBooks, 2015
The current understanding of solidification phenomena is based largely on the differential formul... more The current understanding of solidification phenomena is based largely on the differential formulation of the mechanics of the continuum and the associated conservation of mass, energy, species, and momentum equations. Thus, a short introduction to the fundamentals of transport phenomena as applied to solidification is deemed necessary to facilitate engaging in the intricacies of the subject.
Principles of Thermal Analysis
ASM International eBooks, 2017
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Papers by Doru M Stefanescu