Structural decomposition retarded crystal growth in the undercooled liquid of Zr70Al12.5Fe17.5 metallic glass-forming alloy

The recent attention on crystallization of undercooled glass-forming metallic liquids has been directing to the intriguing viscosity behaviors. The present study discloses that structural decomposition of the grown-out crystalline products plays a part in the crystal growth kinetics. In the supercooled liquid of Zr70Al12.5Fe17.5 metallic glass, the polymorphically crystallizing metastable T2-Zr6Al2Fe phase decomposes into T2 + T2 ' (space group:Amm2, a = 6.895 angstrom, b = 3.368 angstrom, c = 5.119 angstrom), and retards crystal growth. The structure decomposition also occurs in the solidified bulk alloys.