Phase transformation and interface fracture of Cu/Ta multilayers: A molecular dynamics study

Shear Localization and Mechanical Properties of Cu/Ta Metallic Nanolayered Composites: A Molecular Dynamics Study

“…Furthermore, the results at both temperatures demonstrate that the compression strength decreases with an increase in temperature. As the temperature increases, the thermal motion of the atoms intensifies and the bonding of the atoms becomes weaker, which results in an increase in the proportion of amorphous phases [32] and a decrease in the critical stress for dislocation sliding. Therefore, the plastic deformation of the material at 300 K is easier to initiate, and the compressive strength is lower.…”

“…The second is the yielding stage, when the samples yield, the dislocations nucleate at the interface and expand in the matrix, and the dislocation density rises rapidly to its first peak. The third stage is the plastic deformation stage, in which dislocations close to the interface are trapped and the fcc and bcc phases are transformed into amorphous phases [32], all of which lead to a decrease in dislocation density. After that, the proliferation and obliteration of dislocations in the matrix tend to be dynamically balanced, and the dislocation density turns stable.…”

“…This is consistent with the tension studies by Tran et al in their study of dislocation density in Cu/Ta nanostructures. It is because more fcc and bcc phases transform amorphous phases at higher temperatures [32].…”

“…of dislocation density in Cu/Ta nanostructures. It is because more fcc and bcc phases transform amorphous phases at higher temperatures [32]. To reveal the details of the phase transition of Cu/Ta MNCs during compression below and above hC, Figure 9a and b exhibit the phase transition evolution curves for h = 1.25 nm and h = 5.6 nm samples at 300 K, respectively.…”

“…Lu et al investigated the effect of a modulation period (7.4-22.36 nm) on the deformation behavior of Cu/Ta MNCs under uniaxial tension [31]. Tran further systematically explored the effects of temperature, strain rate, and modulation period on the phase transformation and fracture behavior of Cu/Ta MNCs under tension in the vertical and parallel interface directions [32]. However, the length-scale dependency of shear localization mentioned above has not been investigated in Cu/Ta MNCs.…”