The Effects of Oxide Layer on the Joining Performance of CuZr Metallic Glasses

Using molecular dynamics (MD) simulation, the pressure bonding of Cu 54 Zr 46 metallic glass (MG) was performed under the introduction of an oxygen layer at the interface with different thicknesses. The results indicated that the evolution of the oxide layer in the joint zone was consistent with the inverse logarithmic law, which meant that the oxide growth occurred through an ionic drift process. It was also found that the high concentration of oxygen at the interface led to the deterioration of Cu-centered clusters, while the low content of oxygen intensified the backbone of the matrix in the vicinity of base metal. Moreover, the MD outcomes demonstrated that the diffusivity of elements increased with the rise of system temperature, leading to the widening of the joint zone. It was also revealed that an optimized oxygen layer tuned the strain distribution in the joint zone and increased the bonding strength. On the other hand, the thicker oxide layer led to the brittleness of the joint zone, so that a catastrophic failure with a sharp necking event occurred under the tensile loading. In total, this work shed light on the importance of oxide layer and system temperature on the joining performance of MGs.