Physico-Chemical Properties of Zn-Fe Alloy Deposits from an Acid Sulphate Bath Containing Triethanolamine

The composition, properties, structure and morphology of electrodeposited Zn-Fe alloy deposits obtained from an acid sulphate bath containing triethanolamine have been investigated. A bath containing less zinc (20%) produced an alloy deposit with higher zinc content (80%), i.e. anomalous co-deposition process. The composition of alloy remained constant with pH of the plating bath and thickness of the alloy deposit. The cathodic current efficiency depends on plating variables. The shift in deposition potentials of Zn-Fe alloy is a chief cause in the co-deposition process to produce alloy of varying composition. Phase structure determination by X-ray diffraction studies showed a wide variety of inter metallic phases. Zn-Fe alloy showed a superior corrosion resistance than zinc coatings. An alloy containing greater than 40% Fe showed a good paintability. Hardness of the alloy deposits increased with increase in iron content in the alloy. Smooth, uniform and fine grained deposits were obtained for the Zn-Fe alloy containing 20% Fe.

Electrodeposition of Zn-Ni Alloy from Alkaline Sulphate Bath Triethanolamine and Mercaptopyridine

Electrodeposition of Zn-Ni alloy from non-cyanide alkaline sulphate bath containing triethanolamine (TEA) and mercaptopyridine (MPY) under optimized plating conditions such as bath pH, temperature current density and metal ion ratio in the bath produced an alloy deposit with the desired composition of 10-15 %wt. of nickel, alloy of this composition showed good adhesion, high hardness pore free, smooth, uniform and finer grained. Deposition potentials of Zn-Ni alloy lie between the potentials of individual metals. Increase in temperature density decreased the nickel content in the alloy deposit, which with increase in temperature and thickness of the alloy deposit increased nickel content in the alloy deposit. Alloy deposition followed a regular type of co-deposition.

Physico-Chemical Properties of Zn-Ni Alloy Deposits from an Acid Sulphate Bath Containing Ethanolamines

The composition, properties, structure and morphology of electrodeposited Zn-Ni alloy deposits obtained from an acid sulphate bath have been investigated. A bath having higher percentage of nickel (50%) produced an alloy deposit with low percentage of nickel (12%), the percentage of nickel in the alloy deposit increases with current density up to 40 A.dm-2, with further increase in current density, the percentage of nickel shows a downward trend, increase in temperature of the plating bath increases the percentage of nickel in the alloy deposit. The hardness of the alloy deposits increases with increase in nickel content in the alloy, the phase structure of alloy deposit shows the presence of α, η, δ and γ phases. The morphology of Zn-Ni alloy deposits shows uniform and finer grained structure.

Electrodeposition of Sn–In Alloys Involving Deep Eutectic Solvents

Tin–indium alloys represent attractive lead-free solder candidates. They show lower values of melting point than pure indium, so that they are investigated as materials with significant applications potential in the electronic industry. Electrodeposition is a very convenient route to prepare Sn–In alloys. The paper presents several experimental results regarding the electrodeposition of Sn–In alloy coatings involving deep eutectic solvents (DESs), namely using choline chloride-ethylene glycol eutectic mixtures. The influence of the main operating parameters on the Sn–In alloy composition and characteristics are presented. Adherent and uniform Sn–In alloy deposits containing 10–65 wt % In have been obtained on Cu substrates. The In content was found to increase as both the In:Sn molar concentration ratio of ionic species in the electrolyte and the applied temperature increased. The use of pulsed current allowed the use of higher current densities leading to slightly higher values of In content in the alloy deposit. X-ray diffraction (XRD) analysis revealed the presence of InSn4 and In3Sn phases in agreement with the phase diagram. According to thermogravimetric analysis (TGA) measurements, values of melting points in the range of 118.6 and 127.5 °C were obtained depending on the alloy composition. The solder joints’ behavior and alloy coatings corrosion performance were also discussed.

Electroless Ni-Co-Cu-P Alloy Deposition in Alkaline Hypophosphite Based Bath

The use of electroless deposition method to deposit nickel alloy attracts attention due to its uniformity, corrosion resistance in neutral media and low friction. Quaternary nickel alloy deposit can be achieved by adding metal ion additive into the plating bath. Furthermore, the use of alkaline bath can accelerate the deposition rate, and provide sufficient thickness for corrosion protection. In this study, an electroless quaternary nickel alloy is deposited on iron coupons by adding cobalt and copper ions in hypophosphite based Ni-P alkaline bath. The nickel alloy deposit surface morphology is studied using scanning electron microscope (SEM) and x-ray fluorescence (XRF). Corrosion behavior of the nickel alloy is investigated using polarization curve measurement in 3.5wt% NaCl aqueous solution. From the results, the elecroless Ni-Co-Cu-P alloy coating produced at higher plating bah pH is harder than the lower bath pH. Higher Co, Cu and P content in the Ni alloy exhibit broader passive area in the polarization curve measurement results.

Graphite felt modified with electroless Co–Ni–P alloy as an electrode material for electrochemical oxidation and reduction of polysulfide species

Electroless deposition of a Co–Ni–P alloy on the surface of graphite felt filaments was performed in a low-temperature pyrophosphate solution under flow-through conditions. The loading, composition, morphology, and structure of electroless the Co–Ni–P alloy deposit on the filaments of the modified graphite felt were investigated by gravimetric analysis, energy-dispersive X-ray spectroscopy, scanning electron microscopy and X-ray diffraction, respectively. Electrochemical characterization of a graphite felt electrode modified with electroless Co–Ni–P alloy was performed by cyclic voltammetry, chrono-techniques, and the electrochemical impedance spectroscopy test in an aqueous solution of polysulfide composed of the mixture of 1 M Na

ELECTRODEPOSITION BEHAVIOR OF Mn WITH Ni IN ACIDIC SULFATE SOLUTIONS

The influence of Mn 2+/ Ni 2+ mole ratio in electrolytes on the Ni – Mn alloy deposits was studied. The electrodeposition mechanism of Mn with Ni is analyzed by the cyclic voltammogram (CV) and an "induced co-deposition" mechanism is proposed for Ni – Mn alloy electrodeposition. The results show that the Mn content in Ni – Mn alloy deposit and the hardness increased with the increase of Mn 2+/ Ni 2+ mole ratio in electrolytes. When the Mn 2+/ Ni 2+ mole ratio in bath was 2/1, the corrosion current density of the deposit coating was the lowest and the corresponding corrosion potential was higher, and under these conditions the coating with a Mn content of 1.20 wt.% showed good corrosion resistance. The scanning electron microscopy (SEM) of the alloy coatings exhibited that the morphology of Ni – Mn alloy coatings were different from Pure Ni coating, and when Mn 2+/ Ni 2+ was 2/1, the surface was compact and homogeneous.