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 t he film porosity are densification and multilayer structures. These me thods are studied in our laboratories at present. Ion-beam-assisted de position (IBAD) TiN films were deposited changing the angle between th e substrate normal and the ion beam incidence direction. The films wer e characterized by transmission electron microscopy, scanning electron microscopy and X-ray diffraction analyses, the hardness was determine d by means of a dynamic Vickers hardness tester and the corrosion beha viour was evaluated using current-potential measurements in a multicyc le voltammogram mode. The results are strongly dependent on the change s in the crystal orientation induced by the ion flux under different a ngles. Careful optimization may lead to coatings with high hardness an d excellent corrosion protection potential. These results are compared with Ti/TiN multilayers deposited by IBAD and magnetron sputtering an d with a sputtered TiN single layer.