Anodic oxidation of nitrogen-implanted aluminium

A well-known surface modification process of aluminium is anodic oxidation. Further, in recent years, there has been a considerable interest in synthesizing aluminium nitrides by direct implantation in order to modify the tribological properties of aluminium. Since in the wear process of aluminium, oxidation effects play an important role, it has been the scope of the present study to investigate oxidation effects of nitrogen-implanted aluminium. Pure aluminium foils have been bombarded with N beams in the energy range 100-320 keV. The surface stoichiometry was investigated by Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA). At each step of oxidation, the sample composition was measured by using RBS and NRA. The results indicate that the stability of the ion-synthesized nitrides and the thickness of the oxide layer largely depend on the implantation conditions (energy, doses, etc.) and on the field gradient applied during the anodic oxidation process.