Publicação
Zinc-Nickel Alloy Electrodeposition: Influence of Triethanolamine
| Resumo: | Compared to pure zinc plating, zinc alloys provide several advantages. A zinc alloy generally offers superior sacrificial protection to steel since it corrodes more slowly than pure zinc. A search for a non-cyanide zinc plating bath resulted on the development of a zinc nickel sulphamate bath. To obtain better quality zinc-nickel deposits, triethanolamine was added to the bath. In this paper the influence of triethanolamine in zinc-nickel plating from sulphamate bath has been investigated through current efficiency measurements, cyclic voltammetry, scanning electron microscope, and X-ray diffraction techniques. In the presence of triethanolamine in the zinc-nickel sulphamate bath the current efficiency of alloy deposition increased to a maximum of 99% at the current density of 1.5 Adm-2 and thereafter decreased. TEA adsorbed on the electrode surface obeying Henrys isotherm. On mild steel surfaces, uniform smooth slate gray deposit with smaller crystallites was produced, in presence of TEA in solution, and the electrodeposits exhibited additional Zn(OH)2 and g-Ni3Zn22 phases. Hydrogen evolution was suppressed by TEA and thereby current efficiency is increased for alloy deposition. |
|---|---|
| Autores principais: | Ravindran,V. |
| Outros Autores: | Muralidharan,V.S. |
| Assunto: | cyclic voltammetry electrodeposition triethanolamine XRD Zn-Ni |
| Ano: | 2007 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Fundação para a Ciência e Tecnologia |
| Idioma: | inglês |
| Origem: | SciELO Portugal |
| Resumo: | Compared to pure zinc plating, zinc alloys provide several advantages. A zinc alloy generally offers superior sacrificial protection to steel since it corrodes more slowly than pure zinc. A search for a non-cyanide zinc plating bath resulted on the development of a zinc nickel sulphamate bath. To obtain better quality zinc-nickel deposits, triethanolamine was added to the bath. In this paper the influence of triethanolamine in zinc-nickel plating from sulphamate bath has been investigated through current efficiency measurements, cyclic voltammetry, scanning electron microscope, and X-ray diffraction techniques. In the presence of triethanolamine in the zinc-nickel sulphamate bath the current efficiency of alloy deposition increased to a maximum of 99% at the current density of 1.5 Adm-2 and thereafter decreased. TEA adsorbed on the electrode surface obeying Henrys isotherm. On mild steel surfaces, uniform smooth slate gray deposit with smaller crystallites was produced, in presence of TEA in solution, and the electrodeposits exhibited additional Zn(OH)2 and g-Ni3Zn22 phases. Hydrogen evolution was suppressed by TEA and thereby current efficiency is increased for alloy deposition. |
|---|
Atividades financiadas
Não foram encontrados projetos financiados.