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

Autor(es)

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]

Afiliação do(s) autor(es)

^[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

• Tipo de documento: Artigo Científico
• Fonte: SURFACE & COATINGS TECHNOLOGY; v. 287, p. 103-112, FEB 15 2016.
• Citações Web of Science: 10

Resumo

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)

• Processo FAPESP: 13/05821-2 - Estudo da eletrodeposição de ligas ternárias de Fe-Mo-P e Fe-W-P. Caracterização de filmes.
• Beneficiário: Elton Patrick Barbano
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 99/07414-6 - Estudo da eletrodeposição de Cu/Zn a partir de banhos não cianetados: caracterização eletroanalítica, espectrofotométrica, física e morfológica
• Beneficiário: Moacyr Rodrigo H. de Almeida
• Modalidade de apoio: Bolsas no Brasil - Doutorado