Processing and Properties of High-Entropy Alloys and Micro- and Nano-Wires

Abstract

Amorphous and solid-solution phases are both with high entropy; the former is mainly with topological disorder while the later is mainly with chemical disorder. The amorphous phase forms at lower temperatures usually below the eutectic temperature, while the solid-solution phase forms at higher temperatures. Mechanical-alloying results have verified that amorphous and solid-solution phases are the two terminal phases by enough long time of milling of the component elements. The phase formation regions, e.g., amorphous, intermetallic compound, and solid-solution, were summarized from the literature and experimental data, with the parameter of the atomic-size differences, δ, and the parameter of Ω. Recently, the definition of high-entropy alloys (HEAs) was also extended to four components and one of the element may exceed 35%. Wires with diameters at micro- and nanoscale were prepared by the melt-extracted method and thermal-plastic forming method. The dynamic mechanical properties of the wires were evaluated.