Papers by Author: Gen Cang Yang

Abstract: By means of XRD, SEM, FE-SEM, and TEM, the microstructures and growth morphology features of icosahedral quasicrystal for rapidly solidified Mg-Al-Zn system were investigated. It was found that, single icosahedral quasicrystal can be obtained in the Mg-Al-Zn alloys. The icosahedral quasicrystal reveals three typical morphologies: well developed dendrites, coral-like, and petal-like, and its compositions are in a wide range composition with 42.87-48.89 at.%Mg, 13.78-17.03 at.%Al, and 34.22-40.60 at.%Zn. Pentagonal dodecahedron with icosahedral symmetries is seen, and certain steps in pentagonal faces suggest that the planar growth occurs on the pentagonal faces.

Abstract: Metastable phase was observed in as-solidified microstructure of undercooled Fe-Co alloy, provided that the initial undercooling (T) of the melt exceeds the critical value. On this basis, the forming mechanism and stability of metastable phase were investigated. The forming mechanism of metastable phase in undercooled Fe-Co alloy was concluded as cooperative effect of “competitive nucleation—remelting—extensive growth—incomplete solid-state transformation” in this work. With the increase of annealing time, the number and dimension of metastable phase decreased at the same time. Moreover, metastable phase was transformed to stable phase completely when annealing time increased to three hours.