Electrochemical Corrosion Behavior of Ti-N-O Modified Layer on the TC4 Titanium Alloy Prepared by Hollow Cathodic Plasma Source Oxynitriding

Abstract

TC4 alloy is widely used in dental implantation due to its excellent biocompatibility and low density. However, it is necessary to further improve the corrosion resistance and surface hardness of the titanium alloy to prevent surface damage that could result in the release of metal ions into the oral cavity, potentially affecting oral health. In this study, Ti-N-O layers were fabricated on the surface of TC4 alloy using a two-step hollow cathode plasma source oxynitriding technique. This resulted in the formation of TiN, Ti2N, TiO2, and nitrogen-stabilized α(N)-Ti phases on the TC4 alloy, forming a Ti-N-O modified layer. The microhardness of the samples treated with plasma oxynitriding (PNO) was found to be 300–400% higher than that of untreated (UN) samples. The experimental conditions were set at 520 °C, and the corrosion current density of the PNO sample was measured to be 7.65 × 10−8 A/cm2, which is two orders of magnitude lower than that of the UN sample. This indicates that the PNO-treated TC4 alloy exhibited significantly improved corrosion resistance in the artificial saliva solutions.

Tribocorrosion and Surface Protection Technology of Titanium Alloys: A Review

“…The chemical surface heat treatment methods mainly include nitriding, carburizing, oxidating, and boronizing. Nitriding treatment is the most commonly used chemical heat treatment method for titanium metal surfaces, including gas nitriding, plasma nitriding, and laser nitriding [ 183 , 184 , 185 , 186 , 187 , 188 , 189 , 190 , 191 , 192 ]. The nitriding temperature of titanium metal is much higher than that of steel materials.…”

Corrosion Resistance of Titanium Alloys Anodized in Alkaline Solutions

“…Authors have reported that in the cathodic layer occurs a hydrogen evolution; that behavior can sensitize the anodized and provoke a faster anodization dissolution, as is shown for the anodization of Ti-6Al-4V in NaOH. The Ti-6Al-4V anodized in KOH showed regeneration of the passive layer, but a dissolution process occurred, so the passive layer generated is not protective enough [54].…”