Rezumat
CZU 541.13; 621.35
DOI https://doi.org/10.5281/zenodo.1049003
The influence of the quantitative composition of the electrolyte and parameters of the stationary electrolysis on the composition and morphology of Fe-Mo and Fe-Co-Mo alloy coatings obtained from the citrate elecrtolyte containing Fe(III) is investigated. It is shown that pH of the solution is reduced in a range of 4.85–4.30, with the concentration of electrolyte components increa-sing at a constant ratio c(Fe3+):c(Co2+):c(MoO42–): c(Cit3–) = 2:2:1:4 accompanied by decreasing of the molybdenum content in the deposit. Increasing the current density contributes to the rise of molybdenum content in the alloy within the whole electrolyte concentrations range. The surface of Fe-Mo alloys is rough and micro porous, and increasing the current density does not contribute to the significant changes in the surface topography. It is established that formation of ternary alloys is characterized by the concurrent reduction of iron and cobalt ions in the alloy while molybdenum content strongly depends on the current density. The surface of ternary alloy containing metals in a ratio of 3:2:1 of Fe-Co-Mo and the molybdenum content up to 17 at.% is needle-like crystalline, which is typical for cobalt. The atomic percentage of molybdenum increases relative to other metals and the surface becomes micro globular when current density increased. Electrodeposits with metals with a ratio of 2.5:1.5:1.0 of Fe-Co-Mo containing 19–20 at.% of molybdenum are characterized by a more developed and rough surface with a high density of the spheroids.
Кeywords: galvanic deposits, morphology, Fe-Co-Mo alloy, stationary electrolysis, citrate electrolyte.