High-Temperature Oxidation Resistance of PDC Coatings in Synthetic Air and Water Vapor Atmospheres

Milan Parchovianský; Ivana Parchovianská; Peter Švančárek; David Medveď; Mateus Lenz-Leite; Günter Motz; Dušan Galusek

doi:10.3390/molecules26082388

High-Temperature Oxidation Resistance of PDC Coatings in Synthetic Air and Water Vapor Atmospheres

Molecules. 2021 Apr 20;26(8):2388. doi: 10.3390/molecules26082388.

Authors

Milan Parchovianský¹, Ivana Parchovianská¹, Peter Švančárek², David Medveď³, Mateus Lenz-Leite⁴, Günter Motz⁴, Dušan Galusek^{1

2}

Affiliations

¹ Centre for Functional and Surface Functionalised Glass, Alexander Dubček University of Trenčín, Študentská 2, 911 50 Trenčín, Slovakia.
² Joint Glass Centre of the Institute of Inorganic Chemistry Slovak Academy of Sciences, Alexander Dubček University of Trenčín and Faculty of Chemical and Food Technology Slovak University of Technology, Študentská 2, 911 50 Trenčín, Slovakia.
³ Institute of Materials Research, Slovak Academy of Sciences, Watsonova 47, SK-043 53 Košice, Slovakia.
⁴ Ceramic Materials Engineering (CME), University of Bayreuth, D-95440 Bayreuth, Germany.

Abstract

This work is aimed at the development and investigation of the oxidation behavior of ferritic stainless-steel grade AISI 441 and polymer-derived ceramic (PDC) protective coatings. Double-layer coatings of a PDC bond coat below a PDC top coat with glass and ceramic passive fillers' oxidative resistance were studied at temperatures up to 1000 °C in a flow-through atmosphere of synthetic air and in air saturated with water vapor. Investigation of the oxide products formed at the surface of the samples in synthetic air and water vapor atmospheres, at different temperatures (900, 950, 1000 °C) and exposure times (24, 96 h) was carried out on both uncoated steel and steel coated with selected coatings by scanning electron microscopy (SEM) and X-Ray diffraction (XRD). The Fe, Cr₂O₃, TiO₂, and spinel (Mn,Cr)₃O₄ phases were identified by XRD on oxidized steel substrates in both atmospheres. In the cases of the coated samples, m- ZrO₂, c- ZrO₂, YAG, and crystalline phases (Ba(AlSiO₄)₂-hexacelsian, celsian) were identified. Scratch tests performed on both coating compositions revealed strong adhesion after pyrolysis as well as after oxidation tests in both atmospheres. After testing in the water vapor atmosphere, Cr ions diffused through the bond coat, but no delamination of the coatings was observed.

Keywords: PDC coatings; oxidation; synthetic air; water vapor.