Normal thermodynamic theory for solutions begins with the mixing of
component atoms. Many solutions are, however, prepared by mixing together
lumps of the components, each of which might contain millions of identical
atoms. We examine here the way in which a solution evolves from these large
clusters of components, from a purely thermodynamic point of view.
There are some interesting results including the prediction that solution
formation by the mechanical alloying of solid components cannot occur unless
there is a gain in coherency as the particles become small. The nature of the
barrier to mechanical alloying is discovered. There is also the possibility of a
metastable state prior to the achievement of full solution, when the
component atoms prefer like-neighbours.
A. Badmos and H. K. D. H. Bhadeshia, Metallurgical and Materials Transactions A, Vol. 18A (1997) 2189-2194
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