Atomistic simulation of the sliding of a rigid indenter over aluminum with crystalline defects

This work presents a molecular dynamics (MD) study, in which a metallic Aluminum slab body was initially deformed by means of a uniaxial pressure, in order to generate different amounts of crystal defects due to different compression ratios. The crystal defects in the slab were quantified using a local coordination analysis of the atoms in the deformable body at different times of the simulation. The pre-deformed slab was then subjected to indentation by a planar rigid indenter, followed by dry slip of this indenter. The effect of the amount of defects was analyzed in terms of friction and adhesion, by measuring the penetration and the lateral (sliding) forces. The simulation results indicate that the adhesion force between atomic layers and the friction force are affected by the crystal defects density.