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· The solid phase has a concentration
gradient between the center and the surface and its average composition
follows the non-equilibrium solidus shown on the phase diagram. · The final average composition of the
solid must be the same as that of the initial liquid phase, Cu-40
wt % Ni,
as matter is conserved. · All
phase transitions take place at a finite rate and involve the nucleation
and growth of a new phase from an existing one. · The stable phase at any temperature is that with the lowest
Gibbs
function and phases in equilibrium have the same Chemical
Potential. · An important issue in phase transformation
will be the manner in which nucleation and growth takes place. · Material property control of
is possible since their temperature-time history determines their microstructure.
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