The electrochemical properties of metallic glasses

An X-ray photoelectron spectroscopy study of chromium-metalloid alloys—III

Passive films formed in 1N HCI at different potentials on mechanically polished samples of the alloy Fe70Cr10P13C7 were studied by XPS surface analysis. The thickness of the films increases with the applied potential; at 0.4 V/SCE (saturated calomel electrode) a discontinuity is observed. The passive films are enriched in chromium oxyhydroxide; phosphates are incorporated in notable amounts. The substrate underneath the film is enriched in phosphorus. The outstanding corrosion resistance of this alloy may thus be attributed to this enrichment of phosphorus underneath the film, reducing to a great extent the ionic conductivity of the interface, and to the incorporation of phosphates in the passive film.

XPS analysis of passive films on the amorphous alloy Fe70Cr10P13C7 : effect of the applied potential

The results of theoretical and experimental studies on the electronic structure, the nature of interatomic interactions, and the properties of binary metal borides, ternary boron-containing compounds and alloys, and also amorphous binary and multicomponent borides are examined. The prospects for employing the methods of solid-state quantum-chemistry in the description of the fundamental electronic properties of metal borides are discussed. The bibliography includes 255 references.

The chemical bonding and electronic properties of metal borides

XPS investigation of passive films on amorphous FeCr alloys

X‐ray photoelectron spectroscopy was used to examine the composition and chemical state of anodically‐formed corrosion layers on FeNiCrPB amorphous alloys in a 1/2 M Na2SO4 solution with pH 5. Amorphous alloys are highly resistant to corrosion and particular attention was given to the chemical states of Cr and P, the elements known to play a major role in the corrosion resistance. A careful sample transfer procedure was established to minimize changes in the sample during transfer from solution to vacuum. A systematic and reproducible progression of chemical states was observed that was related to structure in the polarization curve and to elemental stability diagrams. The largest change in the P 2p oxidation state occurred between 0 and 700 mVSCE while the Cr2p3/2 oxidation state changed between 700 and 1150 mVSCE. Surface concentrations of P and Fe increased with increasing anodic potential, while concentrations of Ni, Cr, and B decreased.

D. R. Baer

Papers

Chemistry of corrosion layers on amorphous FeNiCrPB alloys