Electrodeposition of CoMoRe alloys from a citrate electrolyte

Autor: O.A. Vyshnevskyi, Valeriy Kublanovsky, Yu. S. Yapontseva
Rok vydání: 2018
Předmět:
Zdroj: Journal of Alloys and Compounds. 766:894-901
ISSN: 0925-8388
Popis: In this study, the electrodeposition of the ternary Co-Mo-Re alloy from a complex citrate electrolyte has been investigated. The effect of solution pH, temperature and current density on the chemical composition, current efficiency and morphology of the obtained coatings is shown. It has been found that depending on the electrolysis parameters, four different types of surface morphology can be obtained. The high-quality bright adherent coatings can be obtained at two pH values. At pH 3.5, an alloy containing Со35.5-Мо4.1-Re60.4 –Со52.9-Мо10.8-Re36.3 аt.% deposits with a current efficiency of 20.3–84.5% at a current density of 20–60 mА сm−2, and at pH 6.3, an alloy containing Со41.0-Мо29.5-Re29.5 deposits with a current efficiency of 47% at a current density of 20 mА сm−2. The optimal temperature for electrolysis is 50 °C. An increase in temperature as well as a decrease in temperature lead to the formation of spherulites. At a temperature of 70 °C, also with an increase in pH to 5.0, a powder of spherical shape with 20–30 μm particle size is formed. At pH over 6.5, fissured deposits are formed.
Databáze: OpenAIRE