Electrochemical corrosion properties of metal alloys used in orthopaedic implants

Abstract

This study concerns an investigation of the corrosion behavior of 316 stainless steel, CoCrMo and Ti6Al4V alloys in simulated body conditions (ringer lactate) at 37°C by the use of Tafel plots, mixed potential and electrochemical impedance spectroscopy (EIS). Ti6Al4V alloy has the highest corrosion resistance followed by CoCr alloy. Ti6Al4V-CoCrMO was the best couple for galvanic corrosion with the minimum galvanic potential and current values according to mixed potential theory and Tafel method. It was concluded that Ti6Al4V was the most suitable material for implant applications in the human body.

Electrochemical Stability and Bioactivity Evaluation of Ti6Al4V Surface Coated with Thin Oxide by EIS for Biomedical Applications

“…Comparing the impedance spectra from the Ti6Al4V alloy and from the pure titanium, it is possible to suppose they have distinct electric behaviors 14,23 . For pure titanium, two time constants are observed, arisen from the internal (compact) and external (porous) oxide layers according to the bi-layer oxide model 20,32 .…”

“…Also EIS diagrams detected a two-layered oxide film comprised of a porous outer layer and a compact inner layer 23 .…”

Tribological and corrosion behaviors of warm- and hot-rolled Ti-13Nb-13Zr alloys in simulated body fluid conditions

“…Nevertheless, this material has three serious problems. 3 First, it possesses a higher modulus of elasticity (110 GPa) compared to bone tissue (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) GPa) leading to stress shielding effect. Second, alloying elements Al and V were reported to have toxicity associated with Alzheimer's disease.…”

“…It should be noted that both WR planes exhibited the lower corrosion current densities (1.11 μA/cm 2 for plane normal to the RD and 1.33 μA/cm 2 for plane parallel to the RD) compared to the HR alloy (1.71 μA/cm 2 ). The corrosion current density is directly proportional to the corrosion rate, 22 indicating the better corrosion resistance of the WR alloy. These results explain the fact that only the HR alloy exhibited the tribocorrosion after the wear test, because …”

In vitro corrosion investigations of plasma-sprayed hydroxyapatite and hydroxyapatite-calcium phosphate coatings on 316L SS

“…So, the material with low carbon content (< 0⋅030%) such as 316L stainless steel is usually used for manufacturing the surgical implants (Hanawa 2002). The reason for its popularity is relative low cost, reasonable corrosion resistance, increased mechanical strength and ease of fabrication (Songur et al 2009;Manivasagam et al 2010). But, these steels are subjected to attack when they are transplanted in highly aggressive human body environment (Aksakal et al 2010).…”