Solidification behavior of decagonal quasicrystal in the undercooled Al72Ni12Co16 alloy melt

摘要

The microstructural evolution of Al72Ni12Co16 alloy at various undercoolings was investigated in this paper. A single-phase decagonal quasicrystal (D-phase) was obtained in the undercooled Al72Ni12Co16 alloy melts. Different microstructure morphologies of the D-phase were formed with increasing undercoolings. Based on Toner's model of the step growth of quasicrystals, the growth mechanisms of the D-phase under various undercoolings were discussed. The D-phases formed at various undercoolings in the undercooled melts show different microstructures owing to the change of preferential growth direction from the quasiperiodic to periodic direction.