Composition Electrolytic Coatings with Given Functional Properties

Abstract

Ternary alloys of cobalt with molybdenum and tungsten deposited from biligand citrate-pyrophosphate electrolyte by pulsed mode exhibit different compositions and surface morphologies depending on current density and on/off time. The structure of binary and ternary alloys was found to be amorphous crystalline, and intermetallic phases Co 7 W 6 and Co 7 Mo 3 were identified in deposits. The coherent-scattering region size of the amorphous part was detected of 2-8 nm. The amorphous structure of ternary alloys and significant content of alloying elements (Mo and W) predetermine improved high corrosion resistance. Corrosion resistance of binary and ternary deposits increases with total content of refractory metals, which associated with molybdenum and tungsten, enhancing corrosion resistance to pitting as well as decreasing in roughness and smoothing out the relief of ternary coatings. Ternary galvanic alloys of cobalt with molybdenum and zirconium with micro-globular morphology with low level of stress and cracks are formed at a current density of 4-6Adm À2 and polarization on/off time 2/10 ms. High corrosion resistance of ternary coatings based on cobalt is caused by the increased tendency to passivity and high resistance to pitting corrosion in the presence of molybdenum and zirconium, as well as the acid nature of their oxides.

Nanoscale electrodeposition: Dimension control and 3D conformality

“…Mukhamedova et al electrodeposited binary and ternary alloys of cobalt with molybdenum and tungsten. [72] Mo and W, which are representative refractory metals, were alloyed with Co through pulsed electrodeposition in the biligand citrate-pyrophosphate electrolyte without temperature rise. Binary Co-Mo and Co-W alloys were well deposited without micro-cracks, and ternary Co-Mo-W alloy had a smoother surface than binary alloys.…”

“…Reprinted with permission. [72] Copyright 2018, Elsevier. (D(i)) Methodological development of atomically dispersed metal catalysts (ADMCs) preparation by electrodeposition.…”

Effect of Electrodeposition Parameters on the Composition and Surface Topography of Nanostructured Coatings by Tungsten with Iron and Cobalt

“…The parameters Ra and Rq for the electrolytic alloy Fe-Co-W are of 0.3, which noticeably exceeds the performance of a binary coating and polished steel substrate. It was previously shown [26,27] that the globular nature of the surface is due to the presence of tungsten in the coating and may be a prerequisite for the high microhardness and catalytic activity of the material.…”

The effect of electrolysis mode on the quantitative and phase composition of Fe–Co–W(Mo) coatings

“…Áàãàòîð³÷íèé äîñâ³ä äîñë³äaeåííÿ á³íàðíèõ ³ òåðíàðíèõ ãàëüâàí³÷íèõ ïîêðèâ³â, çîêðåìà é ìåòàë³â ðîäèíè Ôåðóìó ç òóãîïëàâêèìè êîìïîíåíòàìè, ï³äòâåðäaeóº ïåðåâàãó åëåêòðîë³òè÷íèõ ñïëàâ³â çàâäÿêè åôåêòó íàäàäèòèâíîãî ï³äâèùåííÿ âëàñòèâîñòåé ïîð³âíÿíî ç õàðàêòåðèñòèêàìè ñïëàâîòâ³ðíèõ ìåòàë³â [1,2]. Íàìè ïðîäåìîíñòðîâàíî ï³äâèùåííÿ çíîñî-³ êîðîç³éíî¿ ñò³éêîñò³, ì³êðîòâåðäîñò³ á³íàðíèõ Fe-Mo ³ òåðíàðíèõ Fe-Mo-W ïîêðèâ³â, îñàäaeåíèõ ó ãàëüâàíîñòà-òè÷íîìó ðåaeèì³ ç öèòðàòíèõ åëåêòðîë³ò³â íà îñ-íîâ³ Fe(III), ïîð³âíÿíî ³ç ïîêðèòòÿìè çàë³çîì [3]. Âèá³ð åëåêòðîë³ò³â íà îñíîâ³ Fe(III) äëÿ åëåêòðîîñàäaeåííÿ ñïëàâ³â çàë³çà ç òóãîïëàâêèìè ìåòàëàìè, ÿê³ ââîäÿòü ó ðîç÷èí ó âèãëÿä³ îêñîìå-òàëàò³â, îáóìîâëåíèé îêèñíèìè âëàñòèâîñòÿìè îñòàíí³õ çà â³äíîøåííÿì äî Fe(II) [4], ³ ´ðóíòóºòüñÿ íà ðåçóëüòàòàõ äîñë³äaeåíü åëåêòðîõ³ì³-÷íî¿ ïîâåä³íêè ñèñòåì Fe(III)-öèòðàò ³íøèõ íà-óêîâö³â [5,6].…”