Some Hard or Soft Coatings to Protect the Pristine Biometallic Substrates under Fretting-Corrosion Solicitations: What Should Be the Best Solution?

Abstract

Under tribological conditions in aqueous medium, the contact of materials does involve some degradations of materials. Especially friction under small reciprocal displacement, i.e., fretting corrosion, is occurring; this topic has been highlighted since the 80′s regarding hip implants. Hip prosthesis is assembled from three parts: femoral stem, neck and head. Fretting corrosion or friction corrosion between metallic parts first involves some degradation of the oxides layers. This step is governed by mechanics and it is related to some few minutes. Afterwards the corrosion occurrs enhanced by mechanical degradation. As well focused some oxides and some metallic ions are related to biocompatibility issues. Some strategies are available in order to avoid metal against metal friction and/or fretting. Some hard coatings and some smooth coatings were investigated. The first one is diamond-like carbon (DLC), and the second is a polyetheretherketone (PEEK), polymeric one. The investigations were focused on fretting corrosion solicitations of Ti-6Al-4V vs. Ti-6Al-4V + coating. DLC as a coating delays the corrosion degradation. The PEEK coating does not promote any corrosion degradation of the metallic counter part and more generally any wear.

Highly porous Ti as a bone substitute: Triboelectrochemical characterization of highly porous Ti against Ti alloy under fretting-corrosion conditions

“…200 N presented a hysteresis loop with a bigger area than intermediate loads (85, 127.5 and 170 N) and consequently higher dissipated energy was obtained for 200 N. When the dissipated energy obtained is around 0 (like it was obtained for 85, 127.5 and 170 N), adhesion and partial slip are preponderant phenomena due to changes in the mechanical degradation. Fretting regimes can also be characterized by the ratio obtained between the dissipated energy over the total energy called the A ratio [15]. This energy ratio, defined by Mindlin and Deresiewicz [32] approach, followed by Fouvry et al [17], allows accessing the transition between partial and gross slip regimes.…”

“…porous Ti against Ti alloy can present a different behaviour. In order to obtain a correlation between the mechanical and electrochemical responses according to the displacement amplitude [43], Fig. 7 presented the evolution of the 1st OCP drop when fretting started according with the A ratio.…”

“…The normal load is driven through the contact pressure highlighted in the modular junction. The drawback of some electromagnetic motors is related to the low tangential load that is applied compared with hydraulic machines (more details described elsewhere [13][14][15]). The schematic representation of the fretting-corrosion equipment was illustrated in Fig.…”

Coating technology in hydro-turbines for sediment affected power plants: A review

“…The first is diamond-like carbon (DLC), while the second is a polymeric polyetheretherketone (PEEK). The research is based on fretting corroded stresses of Ti-6Al-4V vs. Ti-6Al-4V + coating [35].…”

An Experimental Study on the Fretting Corrosion Behaviours of Three Material Pairs at Modular Interfaces for Hip Joint Implants

“…Fretting corrosion is a chemical-mechanical process that could cause serious material damage [7][8][9][10]. It is well known that there is widespread fretting corrosion in the conical connection of the ball head and the femoral stem in total hip joints [11][12][13][14][15][16][17][18][19][20]. Similar phenomena also exist in the knee joints, shoulder joints, and spinal fixation that use the modular assembly [21][22][23][24][25][26][27].…”