Published November 1997 | Version v1
Journal article

Pit propagation of nickel and nickel molybdenum alloys

  • 1. Univ. of Alberta, Edmonton, Alberta (Canada). Dept. of Chemical and Materials Engineering
  • 2. McMaster Univ., Hamilton, Ontario (Canada). Brockhouse Inst. for Materials Research

Description

Pit development on nickel and nickel-molybdenum alloys in 0.1 M NaCl + 0.05 M Na2SO4 solution under potentiostatic conditions was studied. When the molybdenum content of nickel-molybdenum alloys is above a threshold value, it has the effect of reducing the current flowing from the surface. Examination by scanning electron microscopy shows the presence of two distinct pit morphologies: terraced faceted pit surfaces resulting from crystallographic dissolution is observed on nickel, while shallow pits with smooth surfaces are formed on Ni-5Mo because of the presence of a salt film at the pit bottom. The experimental results were analyzed according to a model for pit growth. The results quantitatively correlate the conductivity of the pit electrolyte and the conductivity and thickness of the salt film with the dissolution of metal within a pit

Additional details

Publishing Information

Journal Title
Journal of the Electrochemical Society
Journal Volume
144
Journal Issue
11
Journal Page Range
p. 3907-3912.
ISSN
0013-4651
CODEN
JESOAN