Reduction of fretting corrosion of Ti‐6Al‐4V by various surface treatments

Abstract

Titanium and titanium-6% aluminum-4% vanadium (Ti-6Al-4V) are known to be biocompatible and corrosion resistant. However, there have been numerous reports of elevated tissue levels of titanium due to passive dissolution, wear, or fretting corrosion of implants. Studies were undertaken to determine whether the fretting corrosion of Ti-6Al-4V could be reduced by surface treatment of one or both surfaces in a fretting situation. Three different surface treatments were studied: ion implantation, physical vapor deposition nitriding, and plasma ion nitriding. The specimens used were screws fretting against the countersinks of a two-hole plate. Fretting corrosion was assessed by weight loss, by chemical analysis of test solutions, and by scanning electron microscopy. Surface treatment of one component, the screws, resulted in reduction in the release of titanium to only 18-32% of that seen with the untreated controls. Weight loss of the untreated plates fretted against physical vapor deposition nitrided screws and plasma ion nitrided screws was reduced to 31 and 38% of the control, respectively. The weight loss of plasma nitrided screws was only 30% that of the control. Nitriding of both plates and screws resulted in a further decrease in plate weight loss and metal release. Plasma ion nitriding of both components had the most significant effect, with the weight loss and titanium release being only 11 and 2% of the control values, respectively.

Stability of cp‐Ti and Ti‐6Al‐4V alloy for dental implants as a function of saliva pH – an electrochemical study

“…Several studies (Maurer et al. ; Narayanan et al. ) have reported the effectiveness of EIS models in estimating the protectiveness of the oxide film formed on the Ti surface as a function of saliva pH levels.…”

“…Impedance experimental data were fitting with chisquare error <0.001 (Valero Vidal & Igual Muñ oz 2008). Several studies (Maurer et al 1993;Narayanan et al 2007) have reported the effectiveness of EIS models in estimating the protectiveness of the oxide film formed on the Ti surface as a function of saliva pH levels. The evolution of C dl and R p are presented in Fig.…”

Corrosion aspects of metallic implants — An overview

“…Thus, a great deal of research has been performed on the orthodontic materials and has provided warning on the adverse effects of corrosion. (1) Shot-peening or nitriding: It has been recently shown that nitriding can reduce the magnitude of fretting corrosion of Ti-6AI-4V devices [80]. (2) Ion implantation: Implantation of ions helps to harden the surface and improve the resistance to wearaccelerated corrosion phenomenon.…”

The fretting corrosion resistance of PVD surface-modified orthopedic implant alloys

“…Regardless, the properties of the resulting films are greatly influenced by the processing parameters of time, temperature, and pressure. Unfortunately, only a few studies [13][14][15] have investigated the effect of surface modification on the fretting corrosion of modular implants. In these studies, nitrogen ion implantation and various forms of nitriding were used to deposit titanium nitride (TiN) diffusion layers onto Ti6Al4V substrates.…”