Fabrication of Metastable Crystalline Nanocomposites by Flash Annealing of Cu_47.5Zr_47.5Al₅ Metallic Glass Using Joule Heating

• Main Authors: Ilya Okulov, Ivan Soldatov, Ivan Kaban, Baran Sarac, Florian Spieckermann, Jürgen Eckert
• Format: Article
• Language: English
• Published: MDPI AG 2020-01-01
• Series: Nanomaterials
• Subjects: nanocomposite; metallic glass; flash annealing; metastable material; mechanical behaviour
• Online Access: https://www.mdpi.com/2079-4991/10/1/84
• ISSN: 2079-4991

Flash Joule-heating was applied to the Cu_47.5Zr_47.5Al₅ metallic glass for designing fully crystalline metastable nanocomposites consisting of the metastable B2 CuZr and low-temperature equilibrium Cu₁₀Zr₇ phases. The onset of crystallization was in situ controlled by monitoring resistivity changes in the samples. The effect of heating rate and annealing time on the volume fraction of the crystalline phases and mechanical properties of the nanocomposites was studied in detail. Particularly, an increase of the heating rate and a decrease of the annealing time lead to a lower number of equilibrium Cu₁₀Zr₇ precipitates and an increase of tensile ductility. Tailoring of these non-equilibrium microstructures and mechanical properties may not be possible unless one starts with a fully glassy material that opens new perspectives for designing metastable nanomaterials with unique physical properties.