Analysis of Mechanical Behavior and Nanostructural Evolution of the Au/AuAl Alloy Interface

The Au/AuAl alloy interface model was established by classical molecular dynamics simulation, and the uniaxial tensile deformation behavior of the interface model at 300 K and 0.05 angstrom/ps strain rate and the evolution of dislocations in nanostructures were studied in detail. Simulation results show that the initial stress is negative due to the internal stress caused by the lattice mismatch between Al and AuAl alloys. In Au/AuAl alloy interface model, when the plastic deformation in the local region reaches the limit, large internal stress will be generated due to plastic exhaustion and uneven deformation, which makes some atoms leave the lattice position to form many micro-voids. With increasing strain, they will coalesce into cracks. The fracture of perfect interface model is preferentially formed in Al matrix. After the introduction of circular cracks in the interface center region and above the center region of the Perfect-III interface model, cracks propagation occur in AuAl alloy region during the tensile process. Dislocation density tends to increase when the tensile strength exceeds the maximum value. The glide of Shockley partial dislocation is the main mechanism of interface deformation. This study enriches the analysis of nanostructural evolution of Au/AuAl alloy interface and similar interfaces during deformation.

Automated summary

The Au/AuAl alloy interface model was simulated using classical molecular dynamics, and the deformation behavior and dislocation evolution were studied in detail. The results show that the initial stress is negative due to lattice mismatch, and the plastic deformation leads to the formation of micro-voids and cracks. The fracture occurs preferentially in the Al matrix, and the interface cracks propagate in the AuAl alloy region during tension. The increase in strain also leads to an increase in dislocation density.