Sminov, Grain Boundary Segregation in Cu-Sb Alloys, Mater. Eggeler, On the Influence of Small Quantities of Bi and Sb on the Evolution of Microstructure During Swaging and Heat Treatment in Copper, J. Roberts, Micro-Mechanical Measurements of Fracture Toughness of Bismuth Embrittlement Copper Grain Boundaries, Philos. Ruhle, Bismuth Induced Embrittlement of Copper Grain Boundaries, Nat. Williams, Quantitative Compositional Mapping of Bi Segregation to Grain Boundaries in Cu, Acta Mater., 1999, 15–16, p 3999–4008 Sahoo, Impurity Limits in Aluminum Bronzes, Material Technology Laboratory, Canada, 2005 Keiichiro, Influence of Pb, Bi and Si Impurities in Free Cutting Copper Alloys on the Embrittlement at the Intermediate Temperature Range, J. Davis, Copper and Copper Alloys, ASM International, Materials Park, OH, 2001, p 492 Kunding, Copper: Its Trade, Manufacture, Use and Environmental Status, International Copper Association, New York, 1999, p 72 Liu, Mechanics and Mechanisms of Fracture: An Introduction, ASM International, Materials Park, OH, 2005, p 76–77 Ignat, Problemas de fragilización y certificación de cobre (Problems in Fragilization Certification of Copper), Seminar Proceedings, Minor Contaminants in Copper, 2007 (Concepción, Chile), University of Concepcion, 2007, p 14–19Ī. When copper wires are annealed, cuprous oxide particles are also more dispersed in the matrix, and not only segregated and concentrated as occurs in the non-annealed condition, thus diminishing the mechanical fragility effect of the oxide. In addition, to discriminate the effect of oxygen concentration in copper ductility, the used probes or wires must have the same previous deformation and must not have been annealed. In this study, from traction tests on copper wires and observation of their fracture surfaces by means of scanning electron microscopy and energy dispersive spectroscopy, it has been concluded that the principal impurity affecting the ductility of the copper wires is oxygen, which is mainly incorporated during the melting of the cathodes and casting of the rods. However, the results of standard mechanical tests to evaluate ductility show that there is no clear correlation between the content of impurities in the cathodes and the ductility of the copper wires. The main characteristic of cathodic copper is its concentration of impurities because this determines the mechanical properties, i.e., ductility, of the derived copper wires.
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