Effect of nitrogen and molybdenum ion implantation in the tribological behavior of AA7075 aluminum alloy

The aim of the present work is to study the effect of nitrogen and molybdenum implantation in the tribological behaviour of the AA7075 alloy subjected to different structural hardening treatments (T6 and T73).Wear tests, nanoindentation and roughness measurements by interferometric profilometry have been performed. Sliding wear experiments were performed in the mode “pin-on-disk” applying a load of 1 N, and under lubrication conditions. These tests are complemented by the analysis of the wear tracks by SEM and EDS.Our results show that the increase in hardness and elastic modulus induced by nitrogen implantation to a dose of 2 × 1017 N+ ions/cm2 at accelerating voltage of 50 keV, produces a positive effect on wear resistance in T73 temper under lubricant conditions, decreasing slightly the friction coefficient and reducing the specific wear rate about 33%. However, this implantation dose seems not to be sufficient to induce this positive effect on wear resistance in T6 condition.Similarly, in the case of Mo implantation, the low increase in hardness and elastic modulus suggests that the selected dose was not enough to achieve the desired improvement in the tribological behaviour of both tempers.

► Effect of N+ and Mo+ implantation in tribological properties of AA7075 aluminium alloy.
► Formation of aluminium nitride layer by N+ implantation produce hardness increase.
► Hardened layer by Mo+ implantation is attributed to damage cause by ion bombardment.
► T73 temper shows a wear resistant increased after both implantations.
► T6 temper does not show a wear resistant increased after both implantations.