Different three-phase microstructures are observed
in directionally solidified Al–Ag–Cu ternary eutectics composed
of an Ag2Al, an Al2Cu and a solid solution a-Al phase.
Asurvey fromregular to irregular structures is given and some
special, newstructural defects are observed and discussed. An
approach for the quantitative description of the rich variety of
complex three-phase microstructures is suggested including
the defects. Shape factor and specific surface area of the phase
particles are determined and compared for different microstructures