STP516

    Evaluation of the Tendency for Dealloying in Metal Systems

    Published: Jan 1972


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    Abstract

    Literature in the field of dealloying is reviewed. Special emphasis is placed on promising new techniques which appear to have predictive capacity in assessing the likelihood of dealloying. These involve use of electrochemical hysteresis methods to generate experimental potential versus pH diagrams for alloys. Superposition of these experimental diagrams over the theoretical potential versus pH diagrams (Pourbaix diagrams) for the constituent metals of the alloy provides a basis for prediction of the tendency for dealloying as a function of potential and pH. Alpha brass (70Cu-30Zn) in 0.1 M sodium chloride is used as an example. The method provides new insights into the explanation of the mechanisms involved in dezincification. For initially copper-free chloride solutions, ranges of potential are indicated in which selective leaching of zinc predominates, where alloy dissolution with replating is expected, and where alloy dissolution without replating occurs.

    Keywords:

    dezincification, electrochemistry, corrosion, tests, evaluation, copper-containing alloys, brasses, potential theory, pH


    Author Information:

    Verink, ED
    Professor and assistant chairman, University of Florida, Gainesville, Fla.

    Heidersbach, RH
    Construction Engineering Research Laboratory, Champaign, Ill.


    Paper ID: STP35427S

    Committee/Subcommittee: G01.11

    DOI: 10.1520/STP35427S


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