Phase composition and transformation behavior of readily solidified Al–Ni–Fe alloys in α-Al–decagonal phase region

Abstract

The structure and transformation behavior of two series of alloys located in the ternary concentration triangle in the Al–Ni–Fe system between aluminum and decagonal phases with two different periodicities have been investigated. The rapidly solidified alloys have the following compositions: Al 100− x (T-2) x ( x = 10–100) and Al 100− x (T-8) x ( x = 30–100) in which T-2 and T-8 refer to the Al 71.6Ni 23.7Fe 4.7 and Al 75Ni 10Fe 15 single decagonal phase alloys, respectively. No evidence indicating the formation of coexistent decagonal and aluminum phases was found in low and medium decagonal-component contents (Al-rich side), either in the as quenched or in the annealed state. As Fe and Ni increase, the decagonal phase forms. The increase in hardness with the transition-metal content of the decagonal component in different alloys is attributed to solution hardening, formation of the dispersed fcc-Al in amorphous matrix, and the dispersion of hard intermetallics including the decagonal phase.