Microstructural and high-temperature cyclic oxidation response of NiCoCrAlY coatings with and without SiC + ZrB2 reactive-element dispenser. (15th August 2021)

• Record Type: Journal Article
• Authors: Vásquez Hernández, Gabriel Israel; González Albarrán, Marco Aurelio; Rodríguez de Anda, Eduardo; Díaz Guillen, Juan Carlos; Jiménez Alemán, Omar; Portilla Zea, Karla Guadalupe; Olmos, Luis
• Is Part Of: Corrosion science. Volume 189(2021)
• Publication Date: 2021-08-15
• Subjects: Intermetallics -- Cycling oxidation -- XRD -- Interfaces; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2021.109617
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: The SiC-ZrB2 can be used as a reactive-element (Si) compound dispenser. Silicon behaves as a reactive-element reducing the oxidation. Coatings with 1 % SiC-ZrB2 displayed thinner TGO layers and a lower oxidation rate. Silicon seems to promote the stabilization of α-Al2 O3 at earlier stages of oxidation. Abstract: In this study, the microstructural and cyclic-oxidation evolution behavior of bond coats (BC) containing SiC + ZrB2 dispersed particles were evaluated. The SiC + ZrB2 dispersed particles at the oxidation temperature of 1130 °C, dissolved at early stages, stabilizing the beta phase, diminishing the aluminum outward diffusion. The silicon at the BC/TC interface, or very close to it, behaved as a reactive element promoting the rapid formation and stabilization of α-Al2 O3 (TGO), and a second scale layer of mixed oxides and silicon-rich compounds, jointly limiting inward oxygen diffusion and resulting in thinner TGO layers, whose kinetic oxidation follows a sub-parabolic behavior, increasing oxidation life-span.