Stability of the passive state of Ni-Zr glassy alloys

Journal Article · Wed Sep 01 04:00:00 EDT 1993 · Corrosion (Houston); (United States)

DOI:https://doi.org/10.5006/1.3316130· OSTI ID:5630722

Janik-Czachor, M ^[1]

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1. Polish Academy of Sciences, Warsaw (Poland). Inst.of Physical Chemistry

Electrochemical and microscopic investigations provided an insight into the anodic behavior of nickel-zirconium (Ni-Zr) glasses with 25 at% to 70 at% Zr in borate buffer solution containing up to 1 M sodium chloride (NaCl). Stability of the passive state of the glasses was high in the absence of cl[sup [minus]]. Oxygen evolution was observed at sufficiently noble potentials in contrast to the corresponding behavior of crystalline Zr, which formed an insulting film during anodization. Measurements of pit nucleation potential showed Ni-Zr glasses were less resistant to pitting than crystalline Zr at any Cl[sup [minus]] concentration. Glasses of > 50% Zr were less resistant than of crystalline Ni. Pit nucleation potential decreased at [approximately] 8 mV/dec of Cl[sup [minus]] concentration, suggesting chemical breakdown of passivity. However, the short induction period of pitting for Zr-rich alloys was compatible with another mechanism of pit initiation involving structural effects within the passive film at high concentrations of Zr.

• OSTI ID: 5630722
• Journal Information: Corrosion (Houston); (United States), Journal Name: Corrosion (Houston); (United States) Vol. 49:9; ISSN 0010-9312; ISSN CORRAK
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102 -- Metals & Alloys-- Structure & Phase Studies
360105* -- Metals & Alloys-- Corrosion & Erosion
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400400 -- Electrochemistry
ALLOYS
CHEMICAL REACTIONS
CHEMISTRY
CORROSION
CORROSION RESISTANCE
ELECTROCHEMISTRY
GLASS
MICROSTRUCTURE
NICKEL ALLOYS
NUCLEATION
PITTING CORROSION
STABILITY
ZIRCONIUM ALLOYS