Search

In this work, we present the results of electrochemical, Raman, FE-SEM/EDS, and XPS studies of graphene coatings deposited by chemical vapour deposition at atmospheric pressure on Mo foil and Pt-coated Mo foil as catalysts. The results showed that the graphene coating synthesized on Pt-coated molybdenum foil was bi-layer and had fewer defects, while the graphene coating on Mo foil was few-layer with more defects. The corrosion studies indicated that both graphene coatings on bare Mo and Pt-coated Mo exhibited good protective properties and can act as a barrier against corrosion in 0.1 M NaCl. [ABSTRACT FROM AUTHOR]

Highlights: [•] Corrosion protection of stainless steel by MOCVD alumina coatings is investigated. [•] Alumina coatings are amorphous and porosity free. [•] A threshold coating thickness is determined to provide long term corrosion protection. [Copyright &y& Elsevier]

The high temperature oxidation behaviors of chromia-forming alloys (F17Ti and Fe–30Cr alloys) have been studied at 1273 K under isothermal conditions and at 1223 K under cyclic conditions, in air under the atmospheric pressure. To extend the oxidation lifetime, coatings have been applied onto the alloy surfaces. Al2O3 and Cr2O3 films doped with Sm2O3 or Nd2O3 were prepared via the metal-organic chemical vapor deposition technique. Single Cr2O3, Al2O3, Nd2O3 and codeposited Cr2O3–Nd2O3, Al2O3–Nd2O3, Al2O3–Sm2O3 coatings drastically improved the chromia-forming alloy high temperature oxidation behavior, since they decreased the oxidation rate and enhanced the oxide scale adhesion. Results showed that a critical amount of reactive element (Nd or Sm) in chromia or alumina coatings (11–18 at.%) was needed to observe the most effective effect. The fast precipitation of NdCrO3 or NdTi21O38 and the segregation of reactive elements at the chromia grain boundaries slowing down outward cation transport and consequently blocking the chromia grain growth, was supposed to be the main reasons of the beneficial effect ascribed to the reactive elements in chromia scales. [Copyright &y& Elsevier]