Hybrid a-CNH+TiO+TiN-type surface layers produced on NiTi shape memory alloy for cardiovascular applications.

AIM

The goal was to improve the properties of NiTi shape memory alloy to make it suitable for cardiac applications. For this purpose, a hybrid a-CNH+TiO+TiN-type surface layer was produced on NiTi alloy and characterized.

MATERIALS & METHODS: The NiTi alloy subjected to hybrid process combining low-temperature oxynitriding under glow discharge conditions and radio frequency chemical vapor deposition process was examined for microstructure, surface topography, corrosion resistance, wettability and surface-free energy, Ni ion release and platelets adhesion, aggregation and activation.

RESULTS

The hybrid surface layers showed slightly increased surface roughness, better corrosion resistance, a more hydrophobic nature, decreased surface free energy, smaller release of nickel ions and reduced platelets activation.

CONCLUSION

The produced layers could expand the range of NiTi medical applications.