The dependence of hardness and corrosion protection power of ion- beam-assisted deposition TiN coatings on the ion beam impact angle

Hard coatings such as titanium nitride are often porous and therefore not necessarily very corrosion resistant. Possibilities for reducing the film porosity are densification and multilayer structures. These methods are studied in our laboratories at present.

Ion-beam-assisted deposition (IBAD) TiN films were deposited changing the angle between the substrate normal and the ion beam incidence direction.

The films were characterized by transmission electron microscopy, scanning electron microscopy and X-ray diffraction analyses, the hardness was determined by means of a dynamic Vickers hardness tester and the corrosion behaviour was evaluated using current-potential measurements in a multicycle voltammogram mode.

The results are strongly dependent on the changes in the crystal orientation induced by the ion flux under different angles. Careful optimization may lead to coatings with high hardness and excellent corrosion protection potential. These results are compared with Ti/TiN multilayers deposited by IBAD and magnetron sputtering and with a sputtered TiN single layer.