Electrodeposition of CuZn films from free-of-cyanide alkaline baths containing EDTA as complexing agent

Author(s)

de Almeida, Moacyr Rodrigo H. ^[1] ; Barbano, Elton Patrick ^[2] ; Zacarin, Maria G. ^[2] ; de Brito, Matheus M. ^[2] ; Tulio, Paulo Cezar ^[3] ; Carlos, Ivani Aparecida ^[2]

Affiliation

^[1] Fac Integradas Maria Imaculada, Rua Paula Bueno 240, BR-13840040 Mogi Guacu, SP - Brazil

^[2] Univ Fed Sao Carlos, Via Washington Luis Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[3] Univ Tecnol Fed Parana, Ave Alberto Carazzai 1640, BR-86300000 Cornelio Procopio, PR - Brazil

• Document type: Journal article
• Source: SURFACE & COATINGS TECHNOLOGY; v. 287, p. 103-112, FEB 15 2016.
• Web of Science Citations: 10

Abstract

In order to study alternative complexing agents for cyanide in Cu-Zn electrodeposition, electrodeposits from cyanide-free alkaline baths containing EDTA as complexing agent were analyzed. The electrodeposition was carried out under constant current conditions (galvanostatic) on AISI 1010 steel substrates. Electrodeposition process and the deposits were characterized with surface morphological analyses, stripping anodic voltammetries, chemical composition and X-ray diffraction (XRD) analysis. Current efficiencies (CEs) higher than 90% for Cu-Zn electrodeposition were obtained at low deposition current densities (j(dep)) for baths with the highest molar {[}Cu2+]/{[}Zn2+] ratio in solution (70/30). For higher j(dep), smaller CEs were obtained. By scanning electron microscopy, fine-grained deposits were observed at j(dep) of -4.0 and -10.0 mA cm(-2) for deposition charge densities (q(dep)) of 2 and 10 C cm(-2) and for j(dep) of -20 mA cm(-2) only for 2 C cm(-2) in the analyzed range of j(dep) and q(dep). Continuous deposits free of cracks were obtained. Colors of deposits such as: bright golden and dark brown could be obtained, depending on j(dep) and q(dep). Burning of deposits was observed at j(dep) of -80 mA cm(-2) at high q(dep). Semi-quantitative chemical analyses of deposits from Cu70Zn30 baths indicated richer in copper deposits. By XRD analysis CuZn2, Cu0.61Zn0.39, Cu and CuO were detected and no inclusions of ZnO. EDTA has prospects for substituting cyanide, however in a limited range of j(dep) and q(dep). (C) 2015 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 13/05821-2 - Study of electrodeposition of Fe-Mo-P and Fe-W-P ternary alloys. Characterization of films.
• Grantee: Elton Patrick Barbano
• Support Opportunities: Scholarships in Brazil - Doctorate