A molecular dynamics study on the mechanical response of thermal-pressure rejuvenated CuxZr100−x metallic glasses

Abstract

A molecular dynamics study was performed on the mechanical response of thermal-pressure rejuvenated CuxZr100−x metallic glasses. The effect of temperature (50, 300, 600 K) and pressure (0–50 GPa) on the rejuvenation process and the mechanical properties of CuxZr100−x including stress–strain response, shear localization formation and elastic modulus were investigated. The thermal-pressure rejuvenation process involves transitioning the system to a higher potential energy state and a lower atomic volume, demonstrating the significant influence of pressure on rejuvenation. Our findings reveal that increasing pressure at specific temperatures and material compositions results in reduced yield stress and stress drop. They also indicate that with increasing pressure, the system undergoes a transition towards homogeneity, resulting in enhanced ductility compared to its initial amorphous state. Additionally, high temperatures contribute to lower values of Young's, shear, and bulk moduli, as well as decreased yield stress and stress drop. Consequently, the system becomes more homogeneous, promoting rejuvenation. Furthermore, we observed that the final yield strength of the system increases with higher Cu content for all structures at specific pressures and temperatures. The level of rejuvenation is additionally impacted by the amount of Cu, and structures containing varying content of Cu demonstrate varying degrees of rejuvenation. To validate our findings, we utilized Voronoi analysis, which revealed a higher fraction of densely-packed clusters in the samples. Finally, a total of 10 materials properties were calculated and explored using statistical analysis which shows there are different correlations between pressure, temperature and atomic composition with mechanical properties.

Rapid and accurate predictions of perfect and defective material properties in atomistic simulation using the power of 3D CNN-based trained artificial neural networks

“…We have extended our examination to encompass additional mechanical properties that can be derived from the elastic constants, the elastic constants, as described in refs 45 , 46 , and elucidated in the methods section. Comprehensive mechanical behavior regarding these derived properties can be found in the supplementary Information.…”

On the structure and icosahedral interconnectivity in Tantalum monatomic glass produced under pressure

“…Structure analysis of both experiments and simulations has revealed that the SRO of metallic glasses is often described by the presence of icosahedral structures, i.e., a center atom enclosed by 12 atoms, which control many physical properties in these systems [50,51]. Although the atomic structure can be defined through the VA based on the following criteria: the lines that connect the central atom and its nearest neighbors are bisected using a set of planes, constructing thus a polyhedron [38,52]. Each polyhedron i is recognized using the Voronoi index < > n n n n , , ,…”

“…6 in which ( ) = n j 3,4,5,6 i j presents the number of j-edged polygon in Voronoi Polyhedron (VP) i [38,52]. Figure 4 shows the response of the structural atomic packing at SRO in Ta MG to the external pressure ranging from 0 GPa to 70 GPa.…”

Structural Correlation of the Glass‐Forming Ability in a Cu–Zr‐Based Metallic Glass: A Molecular Dynamics Study

“…[1][2][3] Their high strength combined with the good plasticity, supercooled liquid region, and high glass transition temperature makes them attractive materials for functional and practical applications. [4,5] In the same context, Cu-Zr-based MGs have attracted much more attention scientifically and commercially due to their higher glass-forming ability (GFA), their mechanical properties as well as their low cost in the range of materials. [6,7] Improved ductility under compression and exceptional plasticity are also reported for Cu-Zr-based MGs.…”