Fabrication of Metastable Crystalline Nanocomposites by Flash Annealing of Cu47.5Zr47.5Al5 Metallic Glass Using Joule Heating

Abstract

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.

Effect of Sample-Size on the Compression Deformation Behavior of a CuZr-Based Bulk Metallic Glass Composite

“…The content of crystalline phase was roughly estimated by DSC. However, in order to precisely describe this, further experiments are needed to confirm this [23,24]. Figure 3 shows the OM images of the cross-sectional microstructures of the Cu 45 Zr 48 Al 4 Nb 3 BMGC samples with different diameters.…”

“…The content of crystalline phase was roughly estimated by DSC. However, in order to precisely describe this, further experiments are needed to confirm this [23,24].…”

Phase Engineering of Nanostructural Metallic Materials: Classification, Structures, and Applications

“…The controllable preparation of crystal–glass dual-phase materials is technically and theoretically challenging, because the amorphous metal phase is intrinsically metastable. − The spontaneous relaxation nature would induce the crystallization that is sensitive to the composition, pressure, and heating/cooling rate. − In contrast, some amorphous carbides, oxides, and hydroxides are ubiquitous in nature, and corresponding SNDP materials have recently been prepared as efficient HER catalysts. In 2015, Liu et al realized a carbide SNDP-GC material by embedding supernanometer-sized Mo 2 C grains in amorphous nitrogen-rich carbon layers (Figures a,b) .…”