Microscopic structure, dynamics, and wear at metal-metal interfaces in sliding contact.

The "generic embedded atom model" (GEAM) has been investigated recently [Phys. Rev. E 69, 021509 (2004)]] to analyze the qualitative equilibrium and nonequilibrium properties of bulk metals in both undeformed and shear deformed states. In the present work, a natural extension of the GEAM is proposed and applied to characterize the microscopic structure, dynamics, and wear at clean commensurate metal(A) - metal(A) and metal(A) - metal(B) sliding interfaces. Nonequilibrium molecular dynamics simulation, used as a GEAM solver, reveals that the dynamics of dislocations, crystalline domains, and related flow behaviors (stress tensor, shear moduli) are coupled. The rotation of crystal domains is detected to trigger material mixing at the interface in early stages of sliding. Further, we study the dependence of structural changes in inhomogeneous metal interfaces on the relevant model parameters. A relation is established between shear moduli, effective shear rate, and shear stress across the interface.