The Contribution of Electrochemistry for a Better Understanding of the Degradation by Tribocorrosion of Metallic Implant Materials

The ConTribuTion of eleCTroChemisTry for a beTTer undersTanding of The degradaTion by TriboCorrosion of meTalliC implanT maTerialsIn this paper there are presented some results obtained by open circuit potential and electrochemical impedance spectroscopy measurements from studies performed on the behavior of tribocorrosion on metallic implant biomaterials as: 304L stainless steel, Co/nano-CeO 2 nanocomposite layer and Ti6al4V untreated and oxidized alloy to form a nanoporous TiO 2 film.The open circuit potential technique used in measuring the tribocorrosion process provide information on the active or passive behavior of the investigated metallic biomaterial in the biological fluid, before, during friction and after stopping the friction.Thus it clearly show a better behavior of Co/nano-CeO 2 nanocomposite coatings as compared with 304L stainless steel to tribocorrosion degradation in Hank solution; as well the better behavior of nanoporous TiO 2 film formed annodically on Ti6al4V alloy surface as compared with untreated alloy to tribocorrosion degradation in artificial saliva Fusayama Meyer.The slight decrease in polarization resistance value resulted from electrochemical impedance spectroscopy measured during friction in the case of the Co/nano-CeO 2 nanocomposite layer (four times smaller), compared to 304L stainless steel, whose polarization resistance decreased more than 1000 times during friction shows the higher sensitivity of stainless steel to degradation by tribocorrosion.The same behavior is observed when comparing the polarization resistance of untreated titanium alloy recorded during friction that is about 200 hundred times smaller, while the specific polarization resistance of the oxidized alloy with the nanoporous film of titanium oxide, decreases very little during friction, highlighting the beneficial effect of modifying the titanium alloy by anodic oxidation to increase its resistance to the degradation process by tribocorrosion.