Mechanical and Corrosion Behavior of Plasma Electrolytic Oxidation Coatings on AZ31B Mg Alloy Reinforced with Multiwalled Carbon Nanotubes

Merino, C.; D, Benjamín Zuluaga; Rudas, J. S.; D., Hugo A. Estupiñán; R., José M. Herrera; Meza, J. M.

doi:10.1007/s11665-020-04633-z

Cited by 19 publications

(3 citation statements)

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“…For instance, graphene oxide (GO) was successfully introduced into a PEO coating [ 242 , 243 , 244 ], reducing the number of micropores and improving the corrosion resistance due to the increased tortuosity of the electrolyte species diffusion pathway. Similarly, the addition of graphite [ 237 , 245 , 246 ], multi-walled carbon nanotubes (CNT) [ 247 , 248 ], or carbon spheres (CS) [ 249 ] into the electrolyte produced a coating densifying effect, thereby increasing the corrosion resistance while the CNT oxidized during PEO (new). However, the primary benefits of the incorporation of carbon-based particles are enhanced hardness, wear resistance, and heat dissipation [ 247 , 248 , 249 ].…”

Section: Effect Of Energy Input and Electrolyte Composition On Coatin...mentioning

confidence: 99%

“…Similarly, the addition of graphite [ 237 , 245 , 246 ], multi-walled carbon nanotubes (CNT) [ 247 , 248 ], or carbon spheres (CS) [ 249 ] into the electrolyte produced a coating densifying effect, thereby increasing the corrosion resistance while the CNT oxidized during PEO (new). However, the primary benefits of the incorporation of carbon-based particles are enhanced hardness, wear resistance, and heat dissipation [ 247 , 248 , 249 ]. Another innovative idea is the in situ incorporation of nanocontainers loaded with corrosion inhibitors (e.g., halloysite or aluminosilicate nanotubes loaded with benzotriazole, molybdate, or vanadate salts or 8-hydroxyquinoline) [ 250 , 251 , 252 ].…”

Section: Effect Of Energy Input and Electrolyte Composition On Coatin...mentioning

confidence: 99%

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Chromate-Free Corrosion Protection Strategies for Magnesium Alloys—A Review: Part II—PEO and Anodizing

et al. 2022

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Although hexavalent chromium-based protection systems are effective and their long-term performance is well understood, they can no longer be used due to their proven Cr(VI) toxicity and carcinogenic effect. The search for alternative protection technologies for Mg alloys has been going on for at least a couple of decades. However, surface treatment systems with equivalent efficacies to that of Cr(VI)-based ones have only begun to emerge much more recently. It is still proving challenging to find sufficiently protective replacements for Cr(VI) that do not give rise to safety concerns related to corrosion, especially in terms of fulfilling the requirements of the transportation industry. Additionally, in overcoming these obstacles, the advantages of newly introduced technologies have to include not only health safety but also need to be balanced against their added cost, as well as being environmentally friendly and simple to implement and maintain. Anodizing, especially when carried out above the breakdown potential (technology known as Plasma Electrolytic Oxidation (PEO)) is an electrochemical oxidation process which has been recognized as one of the most effective methods to significantly improve the corrosion resistance of Mg and its alloys by forming a protective ceramic-like layer on their surface that isolates the base material from aggressive environmental agents. Part II of this review summarizes developments in and future outlooks for Mg anodizing, including traditional chromium-based processes and newly developed chromium-free alternatives, such as PEO technology and the use of organic electrolytes. This work provides an overview of processing parameters such as electrolyte composition and additives, voltage/current regimes, and post-treatment sealing strategies that influence the corrosion performance of the coatings. This large variability of the fabrication conditions makes it possible to obtain Cr-free products that meet the industrial requirements for performance, as expected from traditional Cr-based technologies.

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Section: Effect Of Energy Input and Electrolyte Composition On Coatin...mentioning

confidence: 99%

Section: Effect Of Energy Input and Electrolyte Composition On Coatin...mentioning

confidence: 99%

Chromate-Free Corrosion Protection Strategies for Magnesium Alloys—A Review: Part II—PEO and Anodizing

et al. 2022

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“…To strengthen the surface condition, previous studies have added reinforcement such as highly dispersed polytetrafluoroethylene, polymethyltrimethoxysilane, and hydroxyapatite particles during Plasma Electrolytic Oxidation (PEO) on magnesium (Mg) or Titanium (Ti) alloy and found that the composite coating displayed improved wear and corrosion resistances [15][16][17]. Additionally, selflubricating substances, including graphite, graphene, and molybdenum disulfide (MoS2), have been used to enhance the antifriction qualities of PEO coatings on Mg alloys [12,[18][19][20][21][22][23][24][25]. A superior selflubricating and corrosion-inhibiting material for metal substrates, graphene oxide (GO) has recently shown growing signs of potential for use [13,[26][27][28].…”

Section: Introductionmentioning

confidence: 99%

Surface Refinement of Aluminium Oxide by Carbon-Based Reinforcement

Liza

Tahir

Yaakob

et al. 2023

ARAM

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This paper clarifies the surface difference and tribological performance of anodic oxide coating reinforced with three different carbon-based sources. With the rising age of oxide coating as one of the strongest metal surface protectors, modification and improvement of this coating have been rapidly explored, including reinforcing carbon-based materials. The lack of literature on how the correlation between the particles' size improves the surface condition and its tribological properties opens up the gap in expanding this coating's potential. In this study, aluminium alloy AA2017 has been chosen as the substrate to be anodized with three different carbon sources: micro-sized graphite, nano-sized graphite, and graphite plate. With a constant 2A current on the DC power supply, the substrate was anodized for 60 minutes in a 20% sulphuric acid electrolyte. The finding shows that the anodic oxide with nano-sized graphite produces the highest hardness surface with almost 50% improvement compared to the unreinforced anodic oxide coating with no visible micro-cracks on the surface observed. Tribologically, the anodic oxide reinforced with micro-sized graphite produced the lowest coefficient of friction and wear rate at 0.4 and 1.25x10-5 mm3/Nm, respectively. The wear track image shows traces of debris that are different for each type of anodic coating that might be influenced by the surface roughness and hardness of the coating.

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