CARBONITRIDE THIN LAYER MATERIALS FOR BIOMEDICAL APPLICATIONS

The invention relates to biocompatible thin layer materials, as mono- and multilayers, based on quaternary compounds of carbonitrides of biocompatible transition metals such as Ti, Zr, Nb, Ta, or Hf used for current biomedical applications, obtained by physical vapour deposition, by magnetron sputtering or cathode arc, in reactive plasma which may contain atoms and ions of titanium, zirconium, niobium, tantalum, hafnium, nitrogen or carbon, depending on the nature of the deposited materials. According to the invention, the materials are made of the following compounds TiZrCN,TiHfCN,TiTaCN,TiNbCN, ZrHfCN, ZrTaCN, ZrNbCN, TaHfCN, TaNbCN and NbHfCN with a wide stoichiometric range 0.9 ≤ (C+N)/(M+M) ≤ 3, with a ratio of atomic concentration of elements C/N in the layer ranging between 0.5...2, with a total thickness of layer ranging between 1...4 μ m, the multilayer materials being formed of 8...120 alternating individual layers of TiZrCN,TiHfCN,TiTaCN,TiNbCN, ZrHfCN, ZrTaCN, ZrNbCN, TaHfCN, TaNbCN or NbHfCN with a thickness ranging between 20...250 nm, with the thickness ratio of individual layers ranging between 0.4...2 and with a total thickness of multilayer in the range of 1...4 μ m, adherent to substrate, critical normal forces measured in scratch adhesion testing being between 30...50 N and having a microhardness in the range of 18...32 GPa, exhibiting an average roughness lower than 10 nm and the value of the cellular viability factor ranging between 90...95% upon cytotoxicity assay. Invenţia se referă la materiale din straturi subţiri biocompatibile, sub formă de mono şi multistrat, pe bază de compuşi cuaternari din carbonitruri ai unor metale de tranziţie biocompatibile, cum sunt Ti, Zr, Nb, Ta sau Hf, folosite pentru aplicaţii boimedicale obişnuite, printr-o metodă de depunere din fază fizică de vapori, prin pulverizare magnetron sau arc catodic, într-o plasmă reactivă care poate conţine atomi şi ioni de titan, zirconiu, niobiu, tantal, hafniu, azot sau carbon, în funcţie de natura materialelor depuse. Materialele conform invenţiei sunt realizate din compuşii TiZrCN, TiHfCN, TiTaCN, TiNbCN, ZrHfCN, ZrTaCN, ZrNbCN, TaHfCN, TaNbCN şi NbHfCN, cu un interval larg de stoichiometrie 0,9 ≤ (C+N)/(M+M) ≤ 3, cu un raport al concentraţiilor atomice ale elementelor C/N în strat cuprins între 0,5...2, cu grosimea totală a stratului cuprinsă între 1...4 μ m, materialele multistrat fiind formate din 8...120 straturi individuale alternate de TiZrCN, TiHfCN, TiTaCN