Solidification occurs in several material processing methods, such as in casting, welding, and laser additive manufacturing of metals, and it controls the nanoand microstructures and the overall properties. Recent advances in experimental and computational modeling techniques have made it possible to more e ectively study atomistic and microscale mechanisms that control the solidification struc...

Experiments using eutectic Sn–3.5% Ag solder paste were conducted with the objective of examining the conjoint influence of copper particles addition and rapid cooling on microstructural development. The composite solder mixture was made by thoroughly mixing a pre-weighed amount of copper particles with a commercial Sn–3.5% Ag solder paste. The experiments were quite similar to the heating and ...

– We present a novel picture of a non isothermal solidification process starting from a molecular level, where the microscopic origin of the basic mechanisms and of the instabilities characterizing the approach to equilibrium is rendered more apparent than in existing approaches based on coarse grained free energy functionalsà la Landau. The system is composed by a lattice of Potts spins, which...

In this paper, a complete three-dimensional numerical model of mold filling and solidification of steel ingots is presented. The risk of powder entrapment and defects formation during filling is analyzed in detail, demonstrating the importance of using a comprehensive geometry, with trumpet and runner, compared to conventional simplified models. By using a case study, it was shown that the simp...

I employ the van der Waals theory of Baus and co-workers to analyze the fast, adiabatic decay of a supercooled liquid in a closed vessel with which the solidification process usually starts. By imposing a further constraint on either the system volume or pressure, I use the maximum-entropy method to quantify the fraction of liquid that is transformed into solid as a function of undercooling and...

Compositionally graded bulk materials of organic polymer blends were prepared by using nonequilibrium self-organization processes with a uniaxial thermal gradient (Bridgman method). The Bridgman method was firstly applied to prepare two kinds of polymeric compositionally graded materials: a polymer/low molecular weight additive system (poly(e-caprolactone) (PCL)/ 4,49-thiodiphenol (TDP)) and a ...

In this paper, model based control of solidification is studied. A one-dimensional model that describes the dynamic response of the solidification rate for a pure substance is developed. The solidification of a metal column is controlled in order to solidify at a desired rate. The manipulated variable is the power to the heater at the top of the casting. A linear PI-controller is implemented an...

Grain structure control is challenging for metal additive manufacturing (AM). Grain structure optimization requires the control of grain morphology with grain size refinement, which can improve the mechanical properties of additive manufactured components. This work summarizes methods to promote fine equiaxed grains in both the additive manufacturing process and subsequent heat treatment. Influ...

G. W. Ao, M. G. Shen, Z. S. Zhang, B. L. Li: College of Materials and Metallurgy, University of Science and Technology Liaoning, Anshan City, China Hollow side wall insulation mathematical model of unidirectional solidification temperature field was carried out. With the aid of finite element analysis software ProCAST, directionally solidified ingot temperature field with hollow lateral wall in...