Diffusion of silver in titanium nitride: Insights from density functional theory and molecular dynamics

The use of self-lubricating titanium nitride and silver (TiN(Ag)) nanocomposite coatings is a promising way to reduce the wear tools employed dry machining operations for hard-to-cut materials/alloys. To achieve an optimal performance, Ag diffusion within matrix needs be carefully controlled, its mechanisms clearly understood. In this paper we density functional theory calculations investigate Ag-related point defects, adhesion energies energy barriers in TiN bulk, surfaces grain boundaries. Classical molecular dynamics simulations have been performed on TiN(Ag) systems using hybrid MEAM/Mie force field, understand relative importance different processes. Our results show that main transport mechanism nanocomposites surface occurring along intergranular spaces.