Corrosion of Pure Magnesium and Binary Magnesium Alloy in Ringer's Solution

Abstract

The work presents monitoring of the corrosion rate for pure magnesium and the binary magnesium alloy Mg72Zn28. Alloying elements with a purity of 99.9% were used. The melting was performed under the protection of inert gas - argon in an induction furnace. The liquid alloy was poured into a copper mold. In order to make amorphous ribbons, the obtained samples in the form of rods were re-melted on a melt spinner machine. The next step was to perform corrosion tests in Ringer's solution. Corrosion tests were carried out at a temperature of 37°C and pH 7.2. The purpose of using Ringer's solution was to recreate the conditions for the body fluids of the human body. The use of the following research methods, such as: OCP (open circuit potential), LSV (linear sweep voltammetry) and EIS (electrochemical impedance spectroscopy), was aimed at determining the corrosion resistance of the tested materials. Tests carried out in Ringer's solution showed that pure magnesium has significantly worse corrosion resistance than the binary Mg72Zn28 alloy. The conducted research also confirmed that the cathodic reaction takes place faster on the surface of amorphous ribbons. It was also confirmed that for both crystalline materials there is diffusion of chloride ions through the corrosion product layer. SEM-EDS tests were performed on the surface of an amorphous ribbon of the Mg72Zn28 alloy after corrosion in Ringer's solution.