Structure and properties of composite surface layers produced on NiTi shape memory alloy by a hybrid method.

A hybrid process that combines oxidation under glow-discharge conditions with ion beam-assisted deposition (IBAD) has been applied to mechanically polished NiTi shape memory alloy in order to produce composite surface layers consisting of a TiO2 layer and an external carbon coating with an addition of silver. The produced surface layers a-C(Ag) + TiO2 type have shown increased surface roughness, improved corrosion resistance, altered wettability, and surface free energy, as well as reduced platelet adhesion, aggregation, and activation in comparison to NiTi alloy in initial state. Such characteristics can be of great benefit for cardiac applications.