ELECTROCHEMICAL BEHAVIOR OF MECHANICALLY ALLOYED Cu-Co AND Cu-Ni ALLOYS

摘要

Mechanically alloyed Cu-50 and 65 at.% Co and Cu-30, 70 and 90 at. % Ni alloys were prepared by ball milling of elemental powder mixtures for 1080 kiloseconds. In order to compare the electrochemical behavior of mechanically alloyed Cu-Co and Cu-Ni alloys with the equilibrium alloys, same composition alloys were also prepared by a melting and casting process. X-ray diffractograms of these alloys showed the formation of one solid solution in the case of mechanically alloyed alloys and the formation of one solid solution and two solid solutions (two phases) in the case of the equilibrium Cu-Ni and Cu-Co alloys, respectively. These alloys were characterized electrochemically by the linear sweep voltammetry technique in acid and basic testing solutions. Voltammograms of mechanically alloyed Cu-Co and Cu-Ni alloys exhibited the presence of a dissolution peak at a potential more noble man that of pure components. This anodic peak is attributed to the formation of only one solid solution in mechanically alloyed alloys. Besides, the current density of dissolution peak observed in mechanically alloyed alloys is higher than that presented by the equilibrium alloys, which suggests that the dissolution rate of the former alloys be fester than mat of the latter alloys.