Electrochemical Production and Corrosion Testing of Amorphous Ni‐P

Ni‐P alloys were prepared by electrodeposition under different conditions on a rotating disk electrode. A variety of alloys were prepared ranging from Ni‐15P to Ni‐25P. An indirect reduction of species in solution involving several steps appears to be favored over the direct reduction at the electrode based on the low P content in the alloy. Energy dispersion x‐ray microanalysis was used to determine composition of the alloy. Transmission electron microscopy and x‐ray diffraction corroborated the amorphous nature of the structure. The physical and chemical homogeneity of the metallic glasses produced electrochemically is substantiated by the absence of electrochemical localized attack. Thus, a passivation mechanism is proposed which explains the formation of a broad range passive film in alkaline medium and also explains the narrow range of the passive film in acid and neutral media.