Copper–zinc electrodeposition in alkaline-sorbitol medium: Electrochemical studies and structural, morphological and chemical composition characterization.

The galvanostatic technique was used to analyze the electrodeposition of Cu–Zn on to AISI 1010 steel electrode from an alkaline-sorbitol bath with various proportions of the metal ions in the bath: Cu70/Zn30, Cu50/Zn50 and Cu30/Zn70. Coloration of Cu–Zn films were whitish golden, light golden, golden/gray depending on the Cu 2+ /Zn 2+ ratios in the electrodeposition bath, deposition current density ( j dep ) and charge density ( q dep ). The highest current efficiency was ∼54.0%, at j dep −1.0 mA cm −2 and q dep 0.40 C cm −2 in the Cu70/Zn30 bath. Energy dispersive spectroscopy indicated that electrodeposits produced from the bath Cu70/Zn30 showed higher Cu content at lower j dep . Also, for same j dep the Cu content increased with q dep . Scanning electron microscopy showed that Cu–Zn electrodeposits of high quality were obtained from the Cu70/Zn30 bath, since the films were fine-grained, except the obtained at j dep −20.0 mA cm −2 and q dep 10.0 C cm −2 . Also, these electrodeposits did not present cracks. X-ray analysis of the Cu–Zn electrodeposits obtained at j dep −8.0, −20.0 and −40.0 mA cm −2 , in each case, with q dep 2.0 and 10.0 C cm −2 , in the Cu70/Zn30 bath, suggested the occurrence of a mixture of the following phases, CuZn, CuZn 5 and Cu 5 Zn 8 . Galvanostatic electrodeposits of Cu–Zn obtained from sorbitol-alkaline baths exhibited whitish golden color, with good prospects for industrial applications, especially for decorative purposes. [ABSTRACT FROM AUTHOR]