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 degrees 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. (C) 2016 Elsevier Ltd. All rights reserved.