Effect of Electrolysis Conditions on the Composition and Microhardness of Ternary Cobalt Alloy Coatings

Abstract

The deposition of Co–W(Mo)–Zr ternary alloys on a copper substrate from pyrophosphate–citrate electrolytes in a pulsed mode has been studied. The effect of temperature, electrolyte pH, and current density on the composition, surface morphology, and current efficiency of ternary electrolytic cobalt alloys with refractory metals has been studied. The resulting coatings have a crack-free uniformly developed surface, which provides a fairly high and reproducible microhardness. It has been found that the size of the globules on the alloy surface decreases with an increase in the current density to 10 A/dm2. It has been revealed that an increase in temperature favorably affects the current efficiency and microhardness of Co–W–Zr coatings. The modes of electrosynthesis of cobalt–tungsten(molybdenum)–zirconium alloy coatings with a desired level of surface development and microhardness have been substantiated.