Creation of a 3D Glassy State by Thermal Gradient Treatment in a Monolithic Metallic Glass

Abstract

In the present article, the creation of a 3D glassy state by gradient thermal history distributed in a monolithic Zr₅₀Cu₄₀Al₁₀ metallic glass using the proposed thermal gradient treatment is discussed. In this thermal method, a rod sample is annealed while sandwiched between BeCu25 jigs and cooled down by tilting contact against a liquid nitrogen-cooled Cu mesh. This allows one side of the edge of the rod sample to cool down rapidly from the supercooled liquid region and introduce a temperature/cooling rate difference in 3D in a single process. Specific heat measurement, indentation test and evaluation of incubation time for crystallization reveal creation of 3D gradients throughout the whole sample. In the present study, a new technique of creating a 3D heterogeneity of glassy state to the desired distribution by gradient thermal history in metallic glasses will be promoted, and the development of functionally graded monolithic bulk metallic glasses will be encouraged in near future.