Plasma-based carbon ion implantation of aluminium at different process times in a pulse-ignited methane plasma

It is well known that aluminium is quite resistant against aqueous corrosion, but suffers from poor tribological properties. A possible solution is the formation of a hard carbide film or deposition of a film of diamond-like carbon. Plasma-based ion implantation with hydrocarbon gases is a method to achieve this, with the particular advantage that this process can be carried out at a low process temperature. Aluminium foil was subjected to plasma-based ion implantation in a methane plasma at a voltage of − 20 kV at process times between 0.5 and 2 h. The particular feature of this experiment was that no external plasma excitation source, such as DC or RF, was applied. The plasma was ignited by the high voltage pulse itself. Glancing incidence X-ray diffraction showed small broad peaks of the carbide phase indicating that the implanted carbon reacted with aluminium to carbide grains of small size. Secondary ion mass spectrometry and X-ray photoelectron spectrometry gave depth profiles of the implanted carbon. The chemical shift of both Al and C photoelectrons proved bond formation.