Electrochemical deposition of cobalt alloy

Electrodeposition of cobalt alloys with refractory metals makes it possible to obtain coatings with a unique combination of physicochemical properties that are unattainable using other deposition methods. For the deposition of high-quality coatings with a cobalt-vanadium alloy, it is proposed to use a citrate electrolyte. Co-V coating was deposited on steel samples from citrate electrolyte at a temperature of 35-40 °C and a current density of 5-12 A/dm2 using soluble cobalt anodes. The vanadium content in the coating deposited at a ligand concentration of 0.3 mol / dm3 is 0.1-0.5 wt%. An increase in the concentration of the ligand to 0.4 mol / dm3 promotes the binding of cobalt into complexes, and, accordingly, the vanadium content in the coating increases to 0.6-1.2 wt.%. Moreover, the tendency to change the percentage of alloying elements with current density remains. Deposition coatings are dense, shiny, without internal stresses and cracks. The proposed compositions of electrolytes and modes of deposition of Co-V coatings with a vanadium content of up to 1.5 wt.% And a current efficiency of 50%. It was found that Co-V coatings are characterized by increased carbon content and are substitutional solid solutions, and the surface morphology of the obtained coatings depends significantly on the current density and changes from fine-crystalline to globular spheroid. The optimal current density for obtaining high-quality coatings with a cobalt alloy in a galvanostatic mode is ік = 10 A / dm2. Management of the storage of galvanic cobalt alloys in a quite wide range of concentrations of alloy-forming components is achieved by varying the electrolysis parameters, which allows the deposition technology to be adapted to the needs of the modern market.