THE pH VALUE EFFECT OF A SIMULATED PHYSIOLOGICAL SOLUTION ON THE CORROSION RESISTANCE OF Ti-6Al-4V ALLOY.

Corrosion is the deterioration of a metal as a result of chemical reactions between it and the surrounding environment. Is a natural process, which converts a refined metal to a more chemically-stable form, such as its oxide, hydroxide, or sulfide. It is the gradual destruction of materials (usually metals) by chemical and/or electrochemical reaction with their environment. Biomaterials are used to replace a part of the body functions lost due to illness or to improve functions and to correct anomalies. The importance of biomaterials has increased due to our innovations in many branches of medicine. Due to its beneficial corrosion resistance, Ti-6Al-4V alloy is widely used in biomedical applications for products intended to come into tissue contact. Even though the corrosion resistance is high, or very high for a given grade, low levels of metals can be released from the Ti-6Al-4V alloy surface in contact with different physiological solutions. One of the important factors that determine the corrosion behavior of metallic biomaterials is the pH of the physiological solution. In situ electrochemical measurements as: open circuit potential (OCP), polarization resistance (Rp), potentiodynamic polarization (PD) and cyclic voltammetry polarization (CV) were performed to monitor the corrosion process. The optical images of the tested samples have been observed before and after corrosion experiments using an optical microscope (Optika) in order to understand the nature of corrosion and the damages produced by this process. [ABSTRACT FROM AUTHOR]