Journal ArticleDOI
The origins of the equiaxed zone—Review of theoretical and experimental work
J. Hutt,David H. StJohn +1 more
TLDR
In a given casting, the mechanism of grain nucleation affects the subsequent development of the grain structure as discussed by the authors, and the mechanism for the formation of equiaxed grains in the absence of grain refining additions is unclear.Abstract:
In a given casting, the mechanism of grain nucleation affects the subsequent development of the grain structure. Despite being well documented in the literature, the mechanism for the formation of equiaxed grains in the absence of grain refining additions is unclear. Controversy still remains regarding the various theories of equiaxed grain formation, none of which have been thoroughly verified. In this paper, previous theoretical and experimental work is critically reviewed. It is concluded that all of the proposed mechanisms can operate depending on the alloy composition, casting conditions and the types of nucleating substrates present in the melt.read more
Citations
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Journal ArticleDOI
The Interdependence Theory: The relationship between grain formation and nucleant selection
TL;DR: The Interdependence Theory as mentioned in this paper links grain formation and nucleant selection to improve the ability to reveal the mechanisms of grain refinement, predict as-cast grain size and account for observations that only a small proportion of added inoculant particles nucleate grains.
Journal ArticleDOI
Macrosegregation in direct-chill casting of aluminium alloys
TL;DR: A post-print version of the final paper published in Progress in Materials Science is available from the link below as discussed by the authors, with a discussion of the quality control mechanisms used in the publishing process.
Journal ArticleDOI
In situ observations of dendritic fragmentation due to local solute-enrichment during directional solidification of an aluminum alloy
TL;DR: In this paper, it was found that streaming of solute-enriched liquid at the tip of high-order branches promotes growth by local undercooling, which causes solute pile-up at the roots of the branches.
Journal ArticleDOI
Columnar to equiaxed grain transition in as solidified alloys
TL;DR: In this article, the columnar to equiaxed transition (CET) in solidified alloys is considered and a review of the current level of understanding of the CET and current modelling capabilities are summarised and assessed.
Journal ArticleDOI
An analytical model for constitutional supercooling-driven grain formation and grain size prediction
TL;DR: In this paper, an analytical model is presented for constitutional supercooling (CS)-driven grain formation with several simplifications, which links the nucleation of new grains to the growth of a larger neighbouring grain.
References
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Journal ArticleDOI
The redistribution of solute atoms during the solidification of metals
TL;DR: In this article, a quantitative analysis of the redistribution of solute resulting from solidification in the absence of convection of a binary solution for transient and steady state conditions is made, where diffusion in the liquid is taken into account and shown to be of importance in determining the solute distribution in both the liquid and the solid.
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Experiments on the solidification structure of alloy castings
TL;DR: In this paper, the grain structure of catalytically clean Ni−Cu alloys is examined as a function of the degree of supercooling below the equilibrium liquidus, and it is concluded that solute elements can promote grain formation in certain castings at supercoolings insufficient to cause heterogeneous nucleation.
Journal ArticleDOI
Origin of the Equiaxed Crystals in Castings
Journal ArticleDOI
The development of macrostructure in ingots of increasing size
TL;DR: In this paper, a series of Al-Cu ingots ranging in volume from approximately 50 to 500 and to 5000 cc have been conventionally prepared in two ways, by normal chill casting or by using a magnetic field to control the convective currents.
Journal ArticleDOI
Origin of the equiaxed zone in small ingots
H. Biloni,B. Chalmers +1 more
TL;DR: In this article, it was deduced by thermal analysis that no entirely new crystals are nucleated in the interior of an ingot at any time after pouring, and the main process for the origin of the equiaxed zone appears to be a multiplication mechanism operating by local remeiting.