Microstructure of Electrodeposited Nickel: Role of Additives

Micro–nanoscale surface microstructure of electrodeposited nickel on AISI 430 substrate from sulfamate bath with ionic and nonionic additives was investigated. 0.69 × 10−4-2.08 × 10−4 M sodium dodecyl sulfate (SDS) and 0.5-4.0 M sodium chloride (NaCl) were used as ionic additives. 0.5-4.0 M ethanol and 1-propanol were used as nonionic additives. Ethanol, propanol, and NaCl promote evolution of nickel micro–nanocones/pyramids. Concentration of these additives, especially NaCl, plays a significant role to modify nickel microstructure. Adhesion of deposited nickel with the substrate, determined by crosscut tape test, is excellent for SDS, ethanol, and propanol additive regardless of their concentration. NaCl degrades the adhesion resulting 100% removal of deposited nickel for 4.0M additive in sulfamate bath. Nickel coating without additive and 1.39 × 10−4 M SDS additive corrode at the same rate (1.08 × 10−2 mm/year), while the other additives increase the corrosion rate.