Effect of molybdenum partitioning on the evolution of microstructure, grain boundary constitution and corrosion behaviour of electrodeposited zinc-molybdenum coatings

Lala, SRF and Singh, AP and Singh, S and Tiwari, SC and Srivastava, C (2023) Effect of molybdenum partitioning on the evolution of microstructure, grain boundary constitution and corrosion behaviour of electrodeposited zinc-molybdenum coatings. In: Materialia, 27 .

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Abstract

Effect of compositional partitioning on microstructural evolution and corrosion behaviour of Zn-Mo coatings (Mo: 2.8 – 6.5 wt) electrodeposited on mild steel substrate has been explored. Corrosion resistance of Zn coating increased with Mo addition until an optimum addition (Zn-4.2 wt Mo) beyond which it decreased for higher Mo content (Zn-6.5 wt Mo). The corrosion current density (icorr) values for pure Zn, Zn-2.8 wt Mo, Zn-4.2 wt Mo, Zn-6.5 wt Mo coating was 17 μA/cm2, 12.25 μA/cm2, 7.5 μA/cm2, 14.2 μA/cm2 respectively. Incorporation of Mo resulted in the formation of Zn-Mo solid solution and Zn3Mo2 compound phases along with segregation of Mo at Zn grain boundaries. High corrosion resistance of Zn-4.2 wt Mo coating was due segregation of Mo at Zn grain boundaries, higher fraction of low angle grain boundaries and coincidence site lattices when compared to the pristine Zn coating. Lower corrosion resistance of Zn-6.5 wt Mo coating was primarily due to higher coating strain because of the solid solution of Mo in Zn and formation of Zn3Mo2 particles in the coating matrix. © 2023 Acta Materialia Inc.

Item Type:	Journal Article
Publication:	Materialia
Publisher:	Elsevier B.V.
Additional Information:	The copyright of this article belongs to Elsevier B.V.
Keywords:	Binary alloys; Corrosion resistant coatings; Corrosive effects; Electrodeposition; Electrodes; Grain boundaries; Molybdenum; Segregation (metallography); Solid solutions; Steel corrosion; Zinc alloys; Zinc coatings; Atom-probe tomography; Corrosion behaviour; Electron back-scattered diffraction; Evolution behavior; Grain-boundaries; Mild steel substrates; Mo additions; Mo coatings; Molybdenum coatings; Zn-mo coating; Corrosion resistance
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	10 Mar 2023 10:03
Last Modified:	10 Mar 2023 10:03
URI:	https://eprints.iisc.ac.in/id/eprint/80921

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