The diffusion behaviors in Mg/Al interface under variated temperatures and surface roughness

To understand the mechanism for controlling of diffusion behaviors in Mg-Al interface of bonding and welding, molecular dynamics method, and embedded atom potential are used to study how the temperature variations and surface roughness affect the diffusion behaviors in Mg-Al interface. Results indicated that the diffusion coefficients of Mg and Al atoms increase with the increase of temperature, which satisfies the Arrhenius formula. The number of diffusion atoms and the diffusion coefficient of Al atoms are higher than Mg atoms, which is caused by the smaller radius of Al atoms and stronger bond of Al atoms. The diffusion coefficient can be increased with the increase of the surface roughness. The pre-filled atoms on the rough surface can enhance the diffusion of Mg-Al interface.