Evaluation of the corrosion resistance of cobalt-based amorphous alloys in an alkaline solution

Cobalt-based amorphous alloys have high corrosion resistance in alkaline solutions due to several key factors. In particular, amorphous alloys do not have a crystal lattice, which excludes the presence of main places for local corrosion. It also significantly reduces the likelihood of formation of microgalvanic pairs, which are the cause of corrosive destruction. Cobalt amorphous alloys often contain chromium, boron, phosphorus and molybdenum, which contribute to the formation of a protective passive film on the surface of the material. In alkaline environments, this film (metal oxides and hydroxides) is stable, which provides durability and resistance to corrosion. Since cobalt and its oxides are highly stable in alkaline environments, this can contribute to electrocatalytic processes. Such alloys are promising for use in electrochemical devices (batteries, fuel cells, etc.). In alkaline environments, due to the high content of cobalt and additional alloying elements, amorphous alloys show special resistance to pitting and crevice corrosion, which is especially important for industrial applications. Due to these properties, amorphous cobalt alloys are used in anti-corrosion coatings, medical implants, as well as in electrochemical and magnetic devices. In the case of using cobalt amorphous alloys as catalysts for the release of hydrogen from alkaline solutions, the corrosion resistance of ribbon amorphous alloys Co72,0Fe5,0Si11,0B12,0, Co72,0Cr5,0Si11,0B12,0, Co70Fe2,5Cr4,5Si11B12 in a 1.0 M aqueous solution of KOH was evaluated for the first time. Electrochemical characteristics of alloys at different speeds of potential scanning were determined.