Friction and Wear Behavior of Aluminum Alloys Ion-implanted with Nitrogen, Oxygen and Metal

6061 aluminum alloy specimens were ionimplanted with nitrogen, oxygen, and mixed gas of nitrogen and hydrogen on a plasma immersion ion implantation (PIII) apparatus operating at different temperatures. They were also ionimplanted with Ti and Al using plasma immersion ion implantation and deposition (MePIID) in lowpressure nitrogen. The chemical states and elemental depth profiles of the modified layers were analyzed by means of Xray photoelectron spectroscopy (XPS). The microhardness and tribological properties of the modified layers were comparatively investigated using the untreated specimen as a control. As the results, the ionimplantation of the Al alloy with O, N, and the mixed gas of nitrogen and hydrogen using PIII greatly increased its microhardness and wearresistance, while the ionimplantation with Ti and Al using MePIID in lowpressure nitrogen also contributed to increase the microhardness and wearresistance of the Al alloy. This was attributed to the formation of a hard Al2O3 layer on the Al alloy surface subject to ionimplantation at different conditions. The composition and depth profile of the Al2O3 layer were largely dependent on the ionimplantation process, especially on the ionimplantation temperature. Thus the modified layers obtained at different ionimplantation temperatures showed differences in the microhardness and wearresistance. The one after oxygen ion implantation at high temperature showed a longer antiwear life, because in this case the Al2O3 surface layer was more compact and thick.