1 Nanostructured Functional Coatings of Iron Family Metals with Refractory. . .
15
Fig. 1.8 Effect of ligand
concentration on composition
Fe-Co-Mo coating deposited
at direct current i = 4 £/ÇÏ 2
Fig. 1.9 Composition ω(M), at.%, and morphology of Fe-Co-Mo coatings deposited in galvanostatic mode from electrolytes of varying concentration at component ratio in electrolyte
c(Fe 3+ ):c(Co 2+ ):c(MoO 4 ) 2− = 2:2:1
Morphology of Fe-Co-Mo deposits varies from fine crystalline to globular with
increasing current density, due to the change in the ratio of alloying metal content in
the alloy (Fig. 1.9). As it was shown earlier (Fig. 1.7), the cobalt and molybdenum
ratio in the alloy changes toward increasing the refractory metal content with current
density. It is established that globular surface appears for deposits with not higher
than twice the prevalence of cobalt portion over molybdenum (Fig. 1.9).
The studies demonstrate that at current amplitude of 2–3 A/dm 2 and the fixed
ratio of the on-/off-time t on /t off = 2 ms/20 ms, the composition of alloy is practically