Localized Ionic Currents from a Corroding Iron-Copper Galvanic Couple.
Abstract
In this report, progress in the application and development of scanning vibrating electrode techniques (SVET) for electrochemical measurements needed to test finite element models is presented. The test system is an iron-copper galvanic couple in which SVET have been used to measure local ionic currents in solution with spatial and current resolutions of the order of 15 to 20 micron and 5nA/sq cm, respectively. Thus, it is possible to measure corrosion currents resulting from individual local cell activity on a scale sufficient to test finite element models for accuracy. The report covers a) a review of the state-of-the-art of scanning vibrating probe techniques, b) an experimental evaluation of the one-dimensional probe technique as applied to planar galvanic couple between iron and copper, and c) a discussion of the development of a three-dimensional probe to advance the state-of-the-art. Based on the completed experimental electric field scans and the corresponding finite element field prediction, it appears that the finite element technique presents a strong analytical tool for calculating the near field distributions about active electrodes surfaces in homogeneous media. Additional keywords: metal matrix composites.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 18, 1985
- Accession Number
- ADA153627
Entities
People
- C. R. Crowe
Organizations
- United States Naval Research Laboratory