Fabrication of metastable crystalline nanocomposites by flash annealing of Cu47.5Zr47.5Al5 metallic glass using joule heating

Flash Joule-heating was applied to the Cu47.5Zr47.5Al5 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. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.EC 111/26-1, MA 3333/13-105K2012European Research Council, ERC: ERC-2013-ADG-340025Funding: This research was funded by the German Federal Ministry of Education and Science BMBF, grant number 05K2012, the German Science Foundation under the Leibniz Program, grant numbers EC 111/26-1 and MA 3333/13-1, and the European Research Council (ERC) under the ERC Advanced Grant INTELHYB, grant number ERC-2013-ADG-340025