The effects of a SiO₂coating on the corrosion parameters cpTi and Ti-6Al-7Nb alloy

Abstract

The aim of this paper was to evaluate the usefulness of the sol-gel method application, to modificate the surface of the Ti6Al7Nb alloy and the cpTi titanium (Grade 4) with SiO2 oxide, applied on the vascular implants to improve their hemocompatibility. Mechanical treatment was followed by film deposition on surface of the titanium samples. An appropriate selection of the process parameters was verified in the studies of corrosion, using potentiodynamic and impedance method. A test was conducted in the solution simulating blood vessels environment, in simulated body fluid at t = 37.0 ± 1 °C and pH = 7.0 ± 0.2. Results showed varied electrochemical properties of the SiO2 film, depending on its deposition parameters. Correlations between corrosion resistance and layer adhesion to the substrate were observed, depending on annealing temperature.

Influence of Surface Modification on Properties of Stainless Steel Used for Implants / Wpływ Modyfikacji Powierzchni Na Właściwości Stali Nierdzewnej Stosowanej Na Implanty

“…On the basis of the obtained results, it was found that regardless of the applied surface treatment the values of critical force causing delamination of the layers was similar and was equal to Lc 3 = 3.80 N (for the polished sample with the Al 2 O 3 layer) and Lc 3 = 3.81 N (for the polished and passivated sample with the Al 2 O 3 layer) respectively - Fig. 3 [12][13][14]. Regardless of the substrate material during the test the acoustic emission signal was not recorded which indicates that the energy of the bond between the coating and the substrate was too low.…”

“…Pitting corrosion test was performed for the samples of the particular variants of surface treatment by potentiodynamic method (recording of anodic polarization curves). On this basis characteristic parameters were set: corrosion potential E kor [ direction of polarization was changed (the return curve was recorded) [12][13][14][15][16].…”

“…Among many techniques of applying layers (sol-gel method [12][13][14], anodic oxidation [15,16]), special attention should be put on ALD (Atomic Layer Deposition) technique, because it allows to control the process of deposition of thin layers and modify their properties by changing the reactants and parameters of the deposition process. The ALD method is distinguished by two features: sequencing of the process and the self-limitation of layers growth.…”

The effect of EO and steam sterilization on the mechanical and electrochemical properties of titanium Grade 4

“…The impedance spectra were analysed with the use of equivalent circuits, and their resultant impedances described ( Figure 4 and Table 2). The best conformity between the model spectra and the experimental spectra obtained from the artificial plasma was achieved in the following circuits: 5,6,11 • circuit indicating the existence of a double layer, where R s is the resistance of the artificial plasma, CPE p is a constant phase element modelling the capacity of the surface zone of the material, with a highly developed surface, R p -an element modelling the solution resistance in this zone, R ct and CPE dlresistance and capacity of the oxide layer (Figure 4a), • circuit including also CPE pore -an element representing the capacity of a double (porous) layer and an R pore resistor representing the electrolytic resistance in the pores (Figure 4b). …”

“…The development and verification of conditions for coating cpTi with layers of TiO 2 and SiO 2 characterized by high hemocompatibility was the topic of previous papers published by the authors. [5][6][7] The safety of a medical device involving contact with blood is also related to the necessity of observing the appropriate procedures, preventing the transfer of pathogenic microorganisms into the human body. Such procedures are aimed at the removal and efficient elimination of microorganisms and the obtaining of sterile medical devices complying with certain specified quality requirements.…”