Liquid–solid equilibria in the quasicrystalline regions of the Al–Pd–Mn phase diagram

Abstract Phase equilibria were investigated in the Al–Pd–Mn phase diagram in the region where quasicrystals and approximant phases form. With respect to previous thermodynamic studies, the extents of the liquidus phase fields of several approximant phases are either established or precisely determined. In particular, compositional profiles across interfaces show the ternary character of the T(AlPdMn) and ξ′ phases which are close to the binary Al–Mn and Al–Pd limits respectively. It is pointed out that the relative stability of some of the phases involves very small energy differences leading to very long transformation times and the solidification of metastable phases.