Enhanced Corrosion Resistance Performance Research Articles

Enhanced corrosion resistance performance of the novel tripodal imidazolium-based ionic liquid: Experimental and theoretical investigations

The imidazolium-based ionic liquids (ILs) were widely recognized as the eco-friendly corrosion inhibitors. Many literatures focused on enhancing the corrosion inhibition efficacy via the modification of various functional groups to ILs. The present study investigated the corrosion resistance performance of the novel synthesized tripodal IL ([(C4im)3TA][Cl3]) with a triazine spacer and three imidazolium cations for mild steel (MS) in 1 M HCl solution. The inhibition efficiencies of [(C4im)3TA][Cl3] at the concentrations of 0.1 mM (55.7 ppm, 80 %) and 0.5 mM (278.5 ppm, 86 %) were found to be comparable to, and higher than that of conventional imidazolium-based ILs 1‑butyl‑3-methylimidazolium chloride (C4mimCl) at 10 mM (1747 ppm, 81 %), respectively. The adsorption behavior of [(C4im)3TA][Cl3] at the metal surface was reflected through X-ray photoelectron spectroscopy, and the adsorption mechanism was further investigated using quantum chemical calculations and molecular dynamics simulations. The results indicated the greater ability of [(C4im)3TA][Cl3] to form chemical bonds with Fe atoms, which induced the generation of the more stable hydrophobic protection film at the surface. This study presented the novel concept for the structural design of high-efficiency corrosion inhibitors based on imidazolium ILs.

Grain Boundary Engineering in Electrodeposited Tin-Carbon Nanotube Composite Coatings for Enhanced Corrosion Resistance Performance

Grain Boundary Engineering in Electrodeposited Tin-Carbon Nanotube Composite Coatings for Enhanced Corrosion Resistance Performance

Deposition Current Density Induced Alterations in Texture and Grain Boundary Constitution of Electrodeposited Zinc Coatings for Enhanced Corrosion Resistance Performance

Deposition Current Density Induced Alterations in Texture and Grain Boundary Constitution of Electrodeposited Zinc Coatings for Enhanced Corrosion Resistance Performance

Electrogalvanization using Zn-graphene oxide composite coatings with enhanced corrosion resistance performance

Zn-based coatings are extensively used for the protection of steel structures. Efforts toward further enhancement in the corrosion resistance performance of Zn coatings are therefore an area of continued interest. In this work, Zn-graphene oxide (Zn-GO) composite coatings containing different volume fractions of GO were electrodeposited on mild steel substrates using an electrolyte bath with different concentrations of dispersed graphene oxide. The electrodeposition parameters used yielded compact and crack-free morphology for all the coatings. Incorporation of GO led to a refinement of the Zn crystallites in the coating matrix. Potentiodynamic polarization measurements clearly showed that all the Zn-GO composite coatings exhibited higher corrosion resistance performance when compared to the pristine Zn coatings, and further, the corrosion rate decreased with the increase in the volume fraction of the GO in the composite coatings.

Electrogalvanization using new generation coatings with carbonaceous additives: progress and challenges

AbstractZinc is an important coating material for corrosion protection of carbon steel because of its sacrificial behavior. Continuous efforts have therefore been made over the years to perform required microstructural engineering to further enhance the corrosion resistance behavior of Zn based coatings. This review is focused on a new class of recently developed coatings in which carbonaceous materials like graphene, graphene oxide and carbon nanotubes (CNTs) are incorporated into Zn metal matrix to significantly affects its electrochemical response. Impermeability of the graphene and graphene oxide and hydrophobicity of the CNTs are the principal reasons behind the adoption of these carbonaceous additives. Over the years, the researchers have, however, observed that the in addition to the above, noticeable microstructural and morphological alterations introduced in the coating matrix due to these carbonaceous additives also contribute significantly to the corrosion resistance behavior. An understanding of the microstructural evolution of the coatings as a function of the additive volume fraction is therefore required to design robust composite coatings with enhanced corrosion resistance performance.

Ascorbic acid peptized alumina sol films with enhanced corrosion resistance performance

Alumina sol was prepared with ascorbic acid (also known as Vitamin C, Vc) as peptizer instead of the traditional used HCl. The prepared sol was then used for the anti-corrosion protection of NdFeB magnets. After substitution, the protective ability of the alumina sol film on NdFeB magnets improved significantly. Systematic comparison of the two alumina sol film were taken. Result showed that the Vc peptized alumina sol (AS-Vc) film showed a more uniform and complete surface which can help repair the defects on NdFeB surface without causing other damages. The electrochemical test showed the corrosion current density of NdFeB with AS-Vc film further reduced to 7.682 × 10−8 A cm-2, which is almost one-third of that in AS-Cl film. Along with the salt-water immersion test result, the data showed the corrosion is obviously suppressed after substitution. What’s more, the differences of the film formation mechanism between the two alumina films were investigated. By comparison, NdFeB in AS-Vc showed an about 200 mV more positive open circuit potential than it in HCl peptized alumina sol (AS-Cl), which means less redox reaction during the film formation process. Above all, the Vc peptized alumina sol provides higher corrosion resistance ability for NdFeB, which is wery suitable for the simple protection of NdFeB materials.

Microstructure and corrosion performance of AlFeCoNiCu high entropy alloy coatings by addition of graphene oxide

High entropy alloys (HEAs) have gained attention due to their exceptional properties. Only a few studies on microstructure-electrochemical property correlation in electrodeposited HEA coatings have been reported so far. Here, AlFeCoNiCu HEA coating containing different amounts of graphene oxide (GO) waselectrodeposited on mild steel substrate and studied. Motivation behind the addition of GO into HEA coatings was to further enhance their corrosion resistance behavior arising primarily from the chemical inertness and impermeability of GO to the passage of corrosive media. As-deposited HEA-GO composite coatings exhibited a granular morphology which became finer and relatively more compact with increase in the GO amount. Structural characterization revealed the presence of mixture of BCC and FCC phase with fraction of the FCC phase increasing with the amount of GO. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) showed that the corrosion rate of HEA-GO coatings progressively decreased with increase in the GO content. Transmission electron microscopy revealed the presence of highly Al-rich matrix phase and Co, Ni, Cu and Fe containing dendritic phase in the coating microstructure. It was noticed that with the addition of GO, the coating microstructure progressively became more compositionally homogeneous. Al distribution between the matrix and dendritic phases became more uniform. Microstructural homogenization which reduced the extent of mutual galvanic coupling between phases and uniform distribution of Al which can form stable and protective alumina phase along with the impermeability properties of GO enhanced corrosion resistance performance of the HEA-GO coatings when compared to pristine HEA coating.

A novel fabrication of superhydrophobic surfaces on aluminum substrate

Superhydrophobic surfaces were successfully fabricated by a simple machine cutting method to create the rough surface and using stearic acid to modify the surface. The products were characterized by scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) Spectroscopy, X-ray photoelectron spectroscopy (XPS) analysis and contact angle (CA) measurements. Potentiodynamic polarization curves were used to reveal corrosion resistance of the samples in 3.5% NaCl aqueous solution. The results showed that the obtained superhydrophobic surfaces all possessed water contact angles of more than 150° and enhanced corrosion resistance performance. A possible formation mechanism of the surface morphologies was proposed through geometric figure. This approach requires no complex processing equipments or time-consuming preparation and no toxic reagents are involved. So this novel and environment-friendly attempt might have promising practical applications.

Application of Self Assembled 6-aminohexanol layers for corrosion protection of 304 stainless steel surface

Grafting of 6-aminohexanol onto a 304 stainless steel substrate was performed with the assistance of polydopamine self assembly. The surface structure of the films was characterized using optical and scanning electron microscopy and X-ray energy dispersive spectroscopy confirmed the establishment of organic films. The corrosion resistance properties were characterized using the electrochemical impedance spectroscopy and potentiodynamic polarization curve measurements. Enhanced corrosion resistance performance was mainly ascribed to the compact film structure and the blocking characteristics against electron transfer of the modified 304 stainless steel substrate.