STRUCTURE OF DIRECTIONALLY FROZEN AL-CUAL2 EUTECTIC ALLOY

Abstract The structure of Al–CuAl2 eutectic alloy has been examined by transmission electron microscopy. The orientations of phases and of preferred lamellar interfaces have been determined and it is shown how small deviations from these preferred orientations are accommodated by tilt and/or twist boundaries. The dislocation structures of sub-boundaries and of the semicoherent phase boundaries are illustrated. The hardness of the eutectic material is more sensitive to the rate of cooling in the solid state than it is to the lamellar spacing and the dislocation distribution in quenched and slowly cooled alloy is compared. © 1969 Taylor & Francis Group, LLC.