Elektrolytisches Korrosionsverhalten metallischer Gläser auf Eisen-, Nickel- und Kobaltbasis

Electrolytical corrosion behaviour of iron-, nickel- and cobalt-base metallic glasses The corrosion behaviour of the three amorphous metals Fe₄₀Ni₄₀B₂₀, Ni₇₈Si₈B₁₄ and Co₅₈Ni₁₀Fe₅Si₁₁B₁₆ was investigated in 0,5 M sulfuric acid and in a boric acid/borax buffer solution. Cyclic voltammograms of the three alloys were measured between hydrogen and oxygen evolution. In case a passive region occurred the corrosion rate in this region was increased by two or three orders of magnitude. Otherwise a potential region with small net current density was observed between hydrogen evolution and active dissolution. This is explained by inhibition of the cathodic partial current density of the hydrogen evolution reaction. All three materials showed increased susceptibility to local corrosion.