In many scientific and engineering problems the solidification of an alloy leads to a highly convoluted crystalline matrix modeled as a thermodynamically controlled reactive porous medium called a mushy layer. We analyze the interaction of an external shear flow with a solidifying mushy layer through a corrugated mush–liquid interface. We find that the external flow can drive forced convective ...

The paper by Karma and Tourret (this volume) in this special issue focuses on multiscale modeling approaches ranging from atoms to microstructure. In the present one, the most recent and significant modeling contributions dealing with the scale of solidification from microstructure to grain structure are briefly reviewed. The paper also covers modeling of defect formation during the last stage ...

Glass fibres with silicon cores have emerged as a versatile platform for all-optical processing, sensing and microscale optoelectronic devices. Using SiGe in the core extends the accessible wavelength range and potential optical functionality because the bandgap and optical properties can be tuned by changing the composition. However, silicon and germanium segregate unevenly during non-equilibr...

High brilliance synchrotron X-ray radiography has been used to in situ study the solidification process of Al­20mass%Cu alloy with nominal spatial and temporal resolutions of 7.4 μm and 300ms, respectively. The block of favorably oriented dendrites by the unfavorably oriented ones was first observed in metal solidification, which related to solute interaction of neighbor dendrites. Solute inter...

The temporal evolution of an interface separating two phases is studied using renormalization group and scaling theory and exact calculation of a sharp interface model incorporating surface tension and kinetic undercooling. Under conditions favoring rapid solidification the characteristic length, R(t), varies as t(1/2) while the total surface area of the interface, S(t), varies as t((d-1)/2). T...

An oscillatory microstructure has been observed during deep-cellular growth of directionally solidified Sn-36at.%Ni hyperperitectic alloy containing intermetallic compounds with narrow solubility range. This oscillatory microstructure with a dimension of tens of micrometers has been observed for the first time. The morphology of this wave-like oscillatory structure is similar to secondary dendr...

Measurements are reported of the liquid and liquid–solid mixture (mush) densities of succinonitrile–acetone (SCN– ACE) alloys for use in crystal growth and solidification studies. The measured data for the liquid is analyzed and consolidated into a correlation that expresses the liquid density as a function of composition and temperature. This correlation also allows for the calculation of the ...

Lotus-type porous nickel with cylindrical pores was fabricated by unidirectional solidification in a mixture gas of hydrogen and argon. The pore size is significantly affected by the addition of NiO powder. The pore size decreases and the number density of the pores increases by the addition of NiO. It is concluded that NiO powder can serve as nucleation sites for the pore formation in the proc...

The paper deals with a numerical modelling of equiaxed microstructure formation during the solidification of two-component alloys. The basic enthalpy formulation was applied to model the solidification. The equiaxed grain size was dependent on the average cooling velocity at the moment when the liquid metal reaches the liquidus temperature. The experimentally determined dependence between grain...

Amplitude representations of a binary phase-field-crystal model are developed for a two-dimensional triangular lattice and three-dimensional bcc and fcc crystal structures. The relationship between these amplitude equations and the standard phase-field models for binary-alloy solidification with elasticity are derived, providing an explicit connection between phase-field-crystal and phase-field...