Corrosion resistance of NiTi shape memory alloy after hybrid surface treatment using low-temperature plasma

This article presents a study of the structure, surface roughness and corrosion resistance of composite layers consisting of a layer of Ti(ON) titanium oxynitride with a surface zone of amorphous carbon modified with nitrogen and hydrogen. They were produced on NiTi alloy in a hybrid process combining oxidation in low-temperature plasma and Radio Frequency Chemical Vapor Deposition process (RFCVD). Ti(ON)+a-CNH type composite layers can be produced in temperatures below 300 °C, i.e. in conditions ensuring that the specific properties of NiTi alloys, namely shape memory and superelasticity, are maintained. They provide a significant increase in corrosion resistance and may be produced on specimens having complex shapes, which is of great importance in the case of possible application as medical implants.