Electrochemical Behavior and Surface Chemistry Studies of Electrodeposited MnMoCrCoFeNiCu High Entropy Alloy-Carbon Nanotube Composite Coatings

Rao, P and Singh, S and Kumar, K and Pandel, U and Srivastava, C (2024) Electrochemical Behavior and Surface Chemistry Studies of Electrodeposited MnMoCrCoFeNiCu High Entropy Alloy-Carbon Nanotube Composite Coatings. In: Journal of Materials Engineering and Performance .

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Abstract

MnMoCrCoFeNiCu high-entropy alloy (HEA)-carbon nanotube (CNT) composite coatings were produced by the electrodeposition route using aqueous electrolyte bath containing different concentrations of dispersed CNTs (0.25, 0.5, 1, 2, 5, 10, 15, 20 mg/l). Morphology, elemental composition, phase constitution, wettability and electrochemical behavior of the composite coatings are correlated. Lower volume fractions of CNTs yielded compact coating morphology and compositional homogeneity. Corrosion rate of the coatings varied non-monotonically with CNT volume fraction and at an optimum volume fraction (for HEAC4 coating: produced from electrolyte with 10 mg/l of CNTs) highest corrosion resistance was observed. Owing to the hydrophobic nature of CNTs, the water contact angle increased from 79.11° for HEA coating to 146.62° for the HEAC4 coating. After the exposure in 3.5 wt. NaCl (corrosive media), the passive oxide layer formed on the CNT-reinforced HEA coatings contains stable oxides of Cr, Mo, Fe and Ni, as compared to the oxides formed over the HEA coating, which reduces the susceptibility of the composite coatings to the 3.5 wt. NaCl corrosive solution. All these factors led to a sharp decline in the corrosion rate from 5.76mpy for the HEA coating to 1.46mpy for HEAC4 coating. Beyond the optimum CNT volume fraction, agglomeration of CNTs led to surface defects and cracks with enhanced corrosion rate. © ASM International 2024.

Item Type:	Journal Article
Publication:	Journal of Materials Engineering and Performance
Publisher:	Springer
Additional Information:	The copyright for this article belongs to Springer.
Keywords:	Chromium alloys; Cobalt alloys; Composite coatings; Contact angle; Copper alloys; Corrosion rate; Corrosion resistance; Corrosion resistant coatings; Electrodeposition; Electrodes; Electrolytes; Entropy; High-entropy alloys; Iron alloys; Manganese alloys; Metal cladding; Morphology; Sodium chloride; Surface chemistry; Surface defects; Volume fraction, Alloy coatings; Aqueous electrolyte; Carbon nanotubes composites; Composites coating; Electrochemical behaviors; Electrochemical surfaces; High entropy alloys; Mnmocrcofenicu high-entropy alloy coating; Optimum carbon nanotube; Stable oxides, Carbon nanotubes
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	11 Jun 2024 09:46
Last Modified:	12 Jun 2024 05:43
URI:	http://eprints.iisc.ac.in/id/eprint/84453

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