The effects of initial rejuvenation on the cold joining behavior of Cu60Zr40 metallic glass

摘要

In this work, the cold joining of Cu60Zr40 metallic glass (MG) was performed by the molecular dynamics (MD) simulation, and the effects of temperature (200-600 K) and joining velocity (6-18 m/s) on the plasticity and mechanical properties of the joint zone were evaluated. Moreover, an initial rejuvenation process was carried out to manipulate the atomic structure of MG to find the role of structural variations on the joining performance. The results indicated that the increase of velocity led to the sharp decline of ultimate strength in the raw-MG joints, while the rejuvenated MG experienced a slight decrease of strength under the rise of velocity. This was due to the fact that the presence of a more defective structure in the rejuvenated sample inhibited the accumulation of local strained regions at the interface in higher velocities. On the other side, the rejuvenated sample was more sensitive to the increase in bonding temperature. At the higher temperatures (500-600 K), the more softening events appeared in the rejuvenated structure, leading to extreme convexity and misalignment in the assemblies. As a result, the strength and plasticity sharply deteriorated in the high temperatures. Finally, it is concluded that the rejuvenated sample is more reliable in the joining process with high velocity; however, it is very sensitive to the bonding temperature.