On the Phase Transformation between the Quasicrystalline to Crystalline Phases in Alloys of Al-Cu-Fe-Co

Abstract

We report in this investigation preliminary results on the phase transformations between the quasicrystalline phases in quaternary alloys of Al-Cu-Fe-Co to crystalline structures. In these alloys obtained by normal casting methods under inert atmospheres both quasicrystalline phases; icosahedral and decagonal are found to coexist. By means of annealing, transformation of the quasicrystalline phases to crystalline structures are induced.Although not quite clear from diffraction patterns along the five-fold and threefold axis, experimental evidence on this crystallization process is clearly obtained along the two-fold axis. The diffraction patterns obtained from the annealed specimens show sign of different degrees of crystallization for different quasicrystalline grains.