Crystal–Melt Interfaces and Solidification Morphologies in Metals and Alloys

MRS Bulletin ◽  
2004 ◽  
Vol 29 (12) ◽  
pp. 935-939 ◽  
Author(s):  
J.J. Hoyt ◽  
M. Asta ◽  
T. Haxhimali ◽  
A. Karma ◽  
R.E. Napolitano ◽  
...  

AbstractWhen liquids solidify, the interface between a crystal and its melt often forms branching structures (dendrites), just as frost spreads across a window. The development of a quantitative understanding of dendritic evolution continues to present a major theoretical and experimental challenge within the metallurgical community. This article looks at key parameters that describe the interface—excess free energy and mobility—and discusses how these important properties relate to our understanding of crystal growth and other interfacial phenomena such as wetting and spreading of droplets and nucleation of the solid phase from the melt. In particular, two new simulation methods have emerged for computing the interfacial free energy and its anisotropy:the cleaving technique and the capillary fluctuation method. These are presented, along with methods for extracting the kinetic coefficient and a comparison of the results to several theories of crystal growth rates.

1981 ◽  
Vol 12 ◽  
Author(s):  
W. F. Kaukler ◽  
J. W. Rutter

The solid-liquid interfacial free energies of each of the individual phases comprising the eutectic system, Carbon Tetrabromide-Hexachloroethane, were measured as a function of composition using a “grain boundary groove” technique. Thermodynamic data were combined with groove shape measurements made from high resolution optical photomicrographs of the solid-liquid interfaces to give the interfacial free energy data. An interfacial free energy balance at the eutectic trijunction was performed to obtain all the forces acting on that point. The three interphase interfacial free energies at the eutectic trijunctions as well as a solid-solid phase boundary torque were evaluated.It was found that the solid-liquid interfacial free energies of the two phases of the eutectic could be evaluated from photomicrographs of growing or stationary eutectic interfaces. In addition, it was found that for a substantial range of freezing conditions the eutectic interface shape can be predicted from a knowledge of the interfacial free energies alone.


1966 ◽  
Vol 44 (8) ◽  
pp. 917-924 ◽  
Author(s):  
A. N. Campbell ◽  
E. M. Kartzmark

A study of the equilibrium freezing-point diagram for the system acetone–bromoform shows that no solid-phase compound forms between acetone and bromoform. The diagram is of the simple eutectic type, the eutectic lying at −101° and 84 mole % acetone. The enthalpies of mixing have been determined for various compositions of mixture and the numerical value of ΔH (per mole of acetone or bromoform) extrapolated to infinite excess of bromoform or of acetone, to obtain the value for completely undissociated complex. This figure is −1.3 kcal per mole of complex (assumed mole to mole). The dipole moments, excess volumes of mixing, viscosities, and total and partial vapor pressures of the system have been measured. From these data, the excess free energy and excess entropy and other thermodynamic functions have been evaluated.


Author(s):  
Wevernilson F. de Deus ◽  
Bruna M. de França ◽  
Josué Sebastian B. Forero ◽  
Alessandro E. C. Granato ◽  
Henning Ulrich ◽  
...  

1994 ◽  
Vol 343 ◽  
Author(s):  
S.C. Wardle ◽  
B.L. Adams ◽  
C.S. Nichols ◽  
D.A. Smith

ABSTRACTIt is well known from studies of individual interfaces that grain boundaries exhibit a spectrum of properties because their structure is misorientation dependent. Usually this variability is neglected and properties are modeled using a mean field approach. The limitations inherent in this approach can be overcome, in principle, using a combination of experimental techniques, theory and modeling. The bamboo structure of an interconnect is a particularly simple polycrystalline structure that can now be readily characterized experimentally and modeled in the computer. The grain misorientations in a [111] textured aluminum line have been measured using the new automated technique of orientational imaging microscopy. By relating boundary angle to diffusivity the expected stress voiding failure processes can be predicted through the link between misorientation angle, grain boundary excess free energy and diffusivity. Consequently it can be shown that the high energy boundaries are the favored failure sites thermodynamically and kinetically.


2019 ◽  
Vol 3 (8) ◽  
pp. 207-213
Author(s):  
Teruaki Motooka ◽  
Shinji Munetoh ◽  
Ryuzo Kishikawa ◽  
Takahide Kuranaga ◽  
Tomohiko Ogata ◽  
...  

1997 ◽  
Vol 11 (02n03) ◽  
pp. 93-106 ◽  
Author(s):  
O. Akinlade

The recently introduced four atom cluster model is used to obtain higher order conditional probabilities that describe the atomic correlations in some molten binary alloys. Although the excess free energy of mixing for all the systems studied are almost symmetrical about the equiatomic composition, most other thermodynamic quantities are not and thus, the study enables us to explain the subtle differences in their physical characteristics required to describe the mechanism of the observed strong heterocoordination in Au–Zn or homocoordination in Cu–Ni within the same framework. More importantly, we obtain all calculated quantities for the whole concentration range thus complimenting experimental evidence.


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