Ni-Co alloy coatings obtained from methanesulfonate electrolytes

It is found that codeposition of nickel and cobalt with alloy formation from methanesulfonate electrolyte occurs with predominant cobalt deposition. The crystalline alloy structure is considerably distorted as compared to pure alloy-forming metals. It is shown that a significant effect on the structure and properties of nickel-cobalt deposits is produced, apart from the alloy composition, by the current density of coating deposition. Comparison of dependences of the alloy composition on current density for methanesulfonate and sulfate electrolytes indicates a smaller change in the content of components in deposits obtained from methanesulfonate electrolyte. The observed small deviations from the constant value of the composition of the Ni-Co alloy deposited from methanesulfonate electrolyte in the current density range of 1–7 A/dm² together with large microhardness values characteristic for these coatings point to extensive prospects of application of methanesulfonate electrolytes for deposition of nickel-cobalt alloys.