Evaluation of oxidation resistant SiC-ZrB2 composite interlayer for plasma sprayed Y2O3 coating over graphite. (September 2021)

• Record Type: Journal Article
• Authors: Madhura B, ; Vetrivendan E, ; Rao, Ch. Jagadeeswara; Ningshen S,
• Is Part Of: Corrosion science. Volume 190(2021)
• Publication Date: 2021-09
• Subjects: A: Ceramic -- B: SEM -- B: Thermal cycling -- B: XRD -- C: Oxidation -- C: Interfaces; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2021.109645
• Languages: English
• ISSNs: 0010-938X

Abstract

Graphical abstract: Highlights: Oxidation resistant SiC-ZrB2 interlayer is successfully deposited on graphite. Adherent Y2 O3 coating over SiC-ZrB2 surface shows good interfacial bonding. Three-fold enhancement in the thermal cycle life of Y2 O3 coating is demonstrated. SiC-ZrB2 show active to passive oxidation behavior by forming glassy SiO2, ZrO2 and ZrSiO4 . Tensile residual mismatch stresses are relieved by the formation of cracks in topcoat. Abstract: The SiC-ZrB2 composite interlayer coating is developed by pack cementation over high density graphite (HDG) for the deposition of plasma sprayed yttria (Y2 O3 ) topcoat for U-Zr (Uranium-Zirconium) melting application. The performance of Y2 O3 coating with interlayer for enhancing its durability are investigated by performing thermal cycling experiments at 1450 and 1550 °C. The interlayer morphology with infiltrated and diffused coating of SiC with entrapped ZrB2 particles reduces the differential thermal mismatch stresses and offers passive oxidation protection for HDG. The role of composite SiC-ZrB2 interlayer enhancing threefold increase in the life of Y2 O3 coating and its mechanisms at high temperature are provided.