Influence of cathodic current density and mechanical stirring on the electrodeposition of Cu-Co alloys in citrate bath

Abstract

Cathodic polarization curves of Cu-Co alloys were galvanostatically obtained on a platinum net, using electrolytes containing copper and cobalt sulfates, sodium citrate and boric acid (pH values ranging from 4.88 to 6.00), with different mechanical stirring conditions. In order to evaluate quantitatively the influence of the applied current density and the mechanical stirring on the cathodic efficiency, the alloy composition for the Cu-Co alloy deposition process, and the average deposition potential, an experimental central composite design 2 2 was employed, and three current density intervals (0.11 to 0.60, 0.50 to 1.98 and 2.44 to 9.94 mA.cm -2 ) were chosen from the polarization curves for this purpose. The results indicated that the current density (mainly in the range between 0.11 and 0.60 mA.cm ), only the average potential was influenced by the current density. On the other hand, the mechanical stirring had a significant effect only on the copper content, for both the lowest (0.11 to 0.60 mA.cm -2 ) and the highest current density range (2.44 to 9.94 mA.cm -2 ). Indeed, in the last range, none of the studied deposition parameters presented significant influence on the studied variables, except for the copper content. This could probably be explained by the direct incorporation of Cu-Citrate complexes in the coating, which was enhanced at high current values.

Electrodeposition of Composite Coatings of Cu/AlO(OH) Using Allyl Alcohol as an Additive

“…However, the hardness value of the coating produced under the conditions of Experiment 5 was smaller than that of pure copper coating. The effect of the leveling agent (AA) could also contributed to this effect, as this additive decreases the amount of defects in copper coatings 37,52,55 . It is interesting to observe that the increase in nanohardness is in opposition to the increase in the anticorrosive protection of the coatings.…”

“…It was an expected result, as the ceramic nanoparticles are known to be able to fill the pores and defects of the metallic coatings, increasing their corrosion resistance 19,21 . Additionally, the presence of AA as a leveling additive may also have contributed to this effect 37,55 . These results also suggest that an increase in the j values and a decrease in S could enhance the particle incorporation in the composite coatings.…”

“…They also provide the necessary statistical inference for a better process efficiency 34,35 . In addition, it is possible to create new coating systems that can fulfill different industrial needs 31,36,37 . Nowadays, several reports can be found in the literature concerning the use of these methodologies to enhance the quality of electrodeposition baths or to achieve realistic optimized conditions 30,[32][33][34][36][37][38][39][40][41] .…”

Electrodeposition of Cobalt Rich Zn-Co alloy Coatings from Citrate Bath

“…Rashwan et al 7 showed that, for the steel polarization in a Zn-Co electrolyte containing glycine 1 mol L -1 , the curve of the alloy lied between those of isolated metals, indicating that glycine electrolyte was able to brought the reduction potentials of the metallic ions together and the nobler metal (cobalt) deposited at less negative potentials, while the less noble metal (zinc) co-deposited at more negative potentials 7,31,32 . Therefore, normal co-deposition would take place, independent of the current density or potential applied.…”

Response surface modeling and voltammetric evaluation of Co-rich Cu–Co alloy coatings obtained from glycine baths

“…The giant magnetoresistance property of these coatings makes them useful for data storage systems and sensor technology [1][2][3]. In addition, the increase in cobalt content in the alloy can also enhance its catalytic and anticorrosive properties [4][5][6][7][8]. However, the production of the electrodeposited coatings, especially alloys and hybrid coatings is always a complex process and for each application, several critical parameters (chemical and operational) must be accurately controlled to fulfill the required characteristics of the produced coating.…”