Microstructures of Directionally Solidified Al–Ag–Cu Ternary Eutectics

Abstract

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.