The Dezincification of Alpha and Beta Brasses

The mechanisms of dezincification of single phase alpha and beta brasses were studied using X-ray diffraction, electron microprobe, metallographic, atomic absorption, and electrochemical techniques. The two mechanisms of dezincification which had been previously reported, (1) dissolution of both alloy constituents followed by redeposition of the more noble species, and (2) the selective removal of the less noble constituent, were found to be operative under certain conditions of potential and pH for both alpha and beta brasses. An electrochemical explanation of the circumstances under which dealloying can be expected to occur was developed based on the use of Pourbaix Diagrams.