engleski

Transition from high-entropy to conventional (TiZrNbCu)1−xCox metallic glasses

In this article, we describe the characterization of a newly fabricated amorphous alloy system (TiZrNbCu)1−xCox covering a broad composition range from high-entropy (HEA) to Co-rich alloys (x ≤ 0.43). We investigated thermal stability, atomic and electronic structure, and magnetic and mechanical properties as a function of chemical composition x. One of the important findings is that all studied properties change their dependence on concentration x within the HEA range. In particular, it has been found that the average atomic volume deviates from Vegard’s law for x > 0.2, the concentration for which the average atomic packing fraction suddenly changes. The valence band structure, studied with ultraviolet photoemission spectroscopy, shows a split-band shape with 3d-states of Co approaching the Fermi level on increasing x. Due to the onset of magnetic correlations, magnetic susceptibility rapidly increases for x > 0.25. Very high microhardness increases rapidly with x. The results are compared with those for similar binary and quinary metallic glasses and with those for Cantor type of crystalline alloys.

Metallic glasses, High entropy alloys, Atomic structure

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