COMPARISON OF FUNDAMENTAL PROPERTIES OF RF-SPUTTERED TINX AND HFNX COATINGS ON STEEL SUBSTRATES

Titanium and hafnium based coatings in this work were sputtered on steel substrates in a r.f. sputtering unit with a diode arrangement. By feeding nitrogen in addition to the inert processing gas argon, TiNx and HfNx coatings were deposited under reactive sputtering conditions. Deposition pressure, nitrogen flow in the chamber and bias voltage on the substrates were systematically varied to get optimized coating systems. The coatings were investigated on their fundamental properties in order to compare titanium and hafnium based films, sputtered under identical process conditions. The results for hardness, deposition rate, internal stress, adhesion, structure, phase analysis and wear show that the properties of HfNx, coatings are less influenced by the deposition process than the coatings of TiNx in the field of selected deposition parameters. The behavior of HfNx, is comparable to TINx, owing to a very similar crystal structure of the materials, but the conclusion of this present paper the well known TINx has to be preferred for tribological applications in mechanical components.