A planar growth with growth directions parallel to a five-fold axis in icosahedral (i) and a ten-fold symmetrical axis in decagonal (D) phases is observed in a melt quenched Al72Pd25Cr3 alloy as well as in stable i-AlCuFe and D-AlNiCo alloys. An interpretation is given on the basis of a stability criterion that the plane perpendicular to the five-fold axis is that of stable growth in an i-phase and the solid-liquid interface instability resulting from the fluctuation of solute concentration occurs during solidification. It leads to the formation of cellular growth along five-fold axis and finally dendritic growth along three-fold morphology.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry