TiO ₂ and SiO ₂ layer deposited by sol-gel method on the Ti6Al7Nb alloy for contact with blood

Purpose: The study contains the analysis of TiO ₂ and SiO ₂ surface modification impact on physical and chemical characteristics of Ti-6Al-7Nb alloy samples in the solution simulating cardiovascular system. Design/methodology/approach: Sol-gel coatings were selected on the ground of data taken from literature. The base of stock solution consisted of silicon dioxide precursor SiO ₂ (TEOS) and titanium oxide precursor TiO ₂. Application of SiO ₂ and TiO ₂ coating on the surface of Ti alloy was preceded by mechanical working - grinding (Ra = 0.40μm) and mechanical polishing (Ra = 0.12μm). Corrosion resistance tests were performed on the ground of registered anodic polarisation curves and Stern method. Electrochemical Impedance Spectroscopy (EIS) was also used in order to evaluate phenomena taking place on the surface of the tested alloys. The tests were made in artificial blood plasma at the temperature of T = 37.0±1°C and pH = 7.0±0.2. Findings: Test results obtained on the ground of voltamperometric and impedance tests showed that electrochemical characteristics of Ti-6Al-7Nb alloy differs relative to the type of surface treatment. Practical implications: Potentiodynamic and EIS studies of corrosion resistance in artificial plasma enable to predict the behavior of modified Ti-6Al-7Nb implants in cardiovascular system. The topic proposed in the article is favourable for the development of entrepreneurship sector due to high demand on such technologies and relatively easy implementation of obtained laboratory test results in the industrial and clinical practice. Originality/value: Suggestion of proper surface treatment variants that incorporate sol-gel method is of perspective significance and will help to develop technological conditions with specified parameters of oxide coating creation on the surface of metallic implants.