Mechanical behavior of Cu—Zr bulk metallic glasses (BMGs): A molecular dynamics approach

Abstract

In the present work, three-dimensional molecular dynamics simulation is carried out to elucidate the nanoindentation behaviors of CuZr Bulk metallic glasses (BMGs). The substrate indenter system is modeled using hybrid interatomic potentials including both many-body Finnis Sinclair (FS) and two-body Morse potentials. A spherical rigid indenter (diameter = 60 Å(1 Å = 10−10 m)) is employed to simulate the indentation process. Three samples of BMGs including Cu25Zr75, Cu50Zr50, and Cu75Zr25 are designed and the metallic glasses are formed by rapid cooling from the melt state at about 2000 K. The radial distribution functions are analyzed to reveal the dynamical evolution of the structure of the atoms with different compositions and different cooling rates. The mechanical behavior can be well understood in terms of load-depth curves and Hardness-depth curves during the nanoindentation process. Our results indicate a positive linear relationship between the hardness and the Cu concentration of the BMG sample. To reveal the importance of cooling rate provided during the processing of BMGs, we investigate the indentation behaviors of Cu50Zr50 at three different quenching rates. Nanoindentation results and radial distribution function (RDF) curves at room temperature indicate that a sample can be made harder and more stable by slowing down the quenching rate.

The Effects of Temperature and Impact Velocity on the Shock Wave Response of Pore-Embedded Metallic Glasses

“…In general, a wide range of CuZr compositions has been constructed in the MD simulation [24]. In the Cu-rich MGs, the plastic deformation is based on the propagation of main shear bands, while the Zr-rich MGs exhibit a homogenous plasticity with an extensive strain led by the generation of multiple shear events in the structure [25].…”

Atomic arrangement in CuZr-based metallic glass composites under tensile deformation

“…38 A developed embedded-atom method (EAM) potential for the Cu-Zr-Al ternary system based on the ab initio calculations has been successfully applied to predict the properties of configurations, such as the crystalline phase, liquids and metallic glasses (MGs), and the EAM-derived results are comparable with both ab initio and experimental data. [39][40][41] The total energy of a solid in EAM is a unique function of electron density, where the total energy of a system is approximated as: 39,42…”

Characterization of Plastic Deformation in CuZr Metallic Glasses Subjected to the Rolling Process

“…It is worth to note that it is possible to simulate a wide range of CuZr composition and prepare various MGs through the MD method. However, we selected the Cu 54 Zr 46 composition with the moderate mechanical properties in the CuZr system [30][31][32].…”