title: Highly Electrically Conducting Glass-Graphene Nanoplatelets Hybrid Coatings.
abstract: Hybrid coatings consisting of a heat resistant Y2O3-Al2O3-SiO2 (YAS) glass containing 2.3 wt % of graphene nanoplatelets (GNPs) were developed by flame spraying homogeneous ceramic powders-GNP granules. Around 40% of the GNPs survived the high spraying temperatures and were distributed along the splat-interfaces, forming a percolated network. These YAS-GNP coatings are potentially interesting in thermal protection systems and electromagnetic interference shields for aerospace applications; therefore silicon carbide (SiC) materials at the forefront of those applications were employed as substrates. Whereas the YAS coatings are nonconductive, the YAS-GNP coatings showed in-plane electrical conductivity (∼10(2) S·m(-1)) for which a low percolation limit (below 3.6 vol %) is inferred. Indentation tests revealed the formation of a highly damaged indentation zone showing multiple shear displacements between adjacent splats probably favored by the graphene sheets location. The indentation radial cracks typically found in brittle glass coatings are not detected in the hybrid coatings that are also more compliant.
authors.affiliation: †Institute of Ceramics and Glass (ICV-CSIC), Kelsen 5, 28049 Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Garcia
authors.affiliation: †Institute of Ceramics and Glass (ICV-CSIC), Kelsen 5, 28049 Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Nistal
authors.affiliation: ‡Aernnova Engineering Solutions Ibérica, Av. de Manoteras 20, 28050 Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Khalifa
authors.affiliation: ‡Aernnova Engineering Solutions Ibérica, Av. de Manoteras 20, 28050 Madrid, Spain.
authors.forename: Y
authors.initials: Y
authors.lastname: Essa
authors.affiliation: ‡Aernnova Engineering Solutions Ibérica, Av. de Manoteras 20, 28050 Madrid, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Martín de la Escalera
authors.affiliation: †Institute of Ceramics and Glass (ICV-CSIC), Kelsen 5, 28049 Madrid, Spain.
authors.forename: M I
authors.initials: MI
authors.lastname: Osendi
authors.affiliation: †Institute of Ceramics and Glass (ICV-CSIC), Kelsen 5, 28049 Madrid, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Miranzo
keywords: electrical conductivity; electromagnetic interference shielding; graphene nanoplatelets; heat resistant glass; hybrid coatings; strain tolerance; thermal protection; thermal spraying