Formation conditions of two quasiperiodic modifications of Al–Pd–Mn icosahedral phase studied by annealing method

Formation conditions of F-phase, F2-phase and F2M-phase were systematically studied at alloy composition of Al71Pd21Mn8 by annealing and succeeding quenching method. The results indicated that the transformation from the F-phase to the F2M-phase occurs in two steps between 734 and 743°C; in the first step the F-phase is transformed to the F2-phase, in the second step the F2-phase is transformed to the F2M-phase. It was reconfirmed that the F-phase is a high-temperature phase stable above approximately 748°C, and the F2M-phase is a low-temperature phase stable below approximately 743°C. The present experiment also indicated that the F2-phase is a transient state between the F-phase and the F2M-phase.