Single crystals of various a-phase Cu-Zn and Cu-Al alloys have been tested for dealloying and stress-corrosion cracking (SCC) in cuprous ammonia solutions. All tests were done at the equilibrium potential of a copper electrode. The dealloying tests were done by scratching coated specimens and measuring the consequent anodic current transients, and the SCC tests used a constant extension rate. The rate of dealloying increased almost discontinuously between 17 and 20 atom percent (a/o) Zn and between 11 and 16 a/o Al. These “parting limits” corresponded identically to the onset of transgranular SCC in both systems. The results support a percolation model of dealloying and a film-induced cleavage model for stress-corrosion cracking.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry