Zr alloy protection against high-temperature oxidation: Coating by a double-layered structure with active and passive functional properties

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F26722445%3A_____%2F19%3AN0000052" target="_blank" >RIV/26722445:_____/19:N0000052 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0010938X19316646" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0010938X19316646</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.corsci.2019.108270" target="_blank" >10.1016/j.corsci.2019.108270</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Zr alloy protection against high-temperature oxidation: Coating by a double-layered structure with active and passive functional properties

Popis výsledku v původním jazyce

In this work, a new concept of metal surface protection against degradation caused by high-temperature oxidation in water environment is presented. We were the first to create a double-layered coating consisting of an active and passive part to protect Zr alloy surface against high-temperature oxidation in a hot water environment. We investigated the hot steam corrosion of ZIRLO fuel cladding coated with a double layer consisting of 500 run nanocrystalline diamond (NCD) as the bottom layer and 2 gm chromium-aluminum-silicon nitride (CrAlSiN) as the upper layer. Coated and uncoated ZIRLO samples were exposed for 4 days at 400 degrees C in an autoclave and for 60 min at 1000 degrees C (nuclear reactor accident temperature) in a hot steam furnace. We have shown that the NCD coating protects the Zr alloy surface against oxidation in an active way: carbon from NCD layer enters the Zr alloy surface and, by changing the physical and chemical properties of the Zr cladding tube surface, limits the Zr oxidation process. In contrast, the passive CrAlSiN coating prevents the Zr cladding tube surface from coming into physical contact with the hot steam. The advantages of the double layer were demonstrated, particularly in terms of hot (accident-temperature) oxidation kinetics: in the initial stage, CrAlSiN layer with low number of defects acts as an impermeable barrier. But after a longer time (more than 20 min) the protection by more cracked CrAlSiN decreases. At the same time, the carbon from NCD strongly penetrates the Zr cladding surface and worsen conditions for Zr oxidation. For the double-layer coating, the underlying NCD layer mitigates thermal expansion, reducing cracks and defects in upper layer CrAlSiN.

Název v anglickém jazyce

Zr alloy protection against high-temperature oxidation: Coating by a double-layered structure with active and passive functional properties

Popis výsledku anglicky

In this work, a new concept of metal surface protection against degradation caused by high-temperature oxidation in water environment is presented. We were the first to create a double-layered coating consisting of an active and passive part to protect Zr alloy surface against high-temperature oxidation in a hot water environment. We investigated the hot steam corrosion of ZIRLO fuel cladding coated with a double layer consisting of 500 run nanocrystalline diamond (NCD) as the bottom layer and 2 gm chromium-aluminum-silicon nitride (CrAlSiN) as the upper layer. Coated and uncoated ZIRLO samples were exposed for 4 days at 400 degrees C in an autoclave and for 60 min at 1000 degrees C (nuclear reactor accident temperature) in a hot steam furnace. We have shown that the NCD coating protects the Zr alloy surface against oxidation in an active way: carbon from NCD layer enters the Zr alloy surface and, by changing the physical and chemical properties of the Zr cladding tube surface, limits the Zr oxidation process. In contrast, the passive CrAlSiN coating prevents the Zr cladding tube surface from coming into physical contact with the hot steam. The advantages of the double layer were demonstrated, particularly in terms of hot (accident-temperature) oxidation kinetics: in the initial stage, CrAlSiN layer with low number of defects acts as an impermeable barrier. But after a longer time (more than 20 min) the protection by more cracked CrAlSiN decreases. At the same time, the carbon from NCD strongly penetrates the Zr cladding surface and worsen conditions for Zr oxidation. For the double-layer coating, the underlying NCD layer mitigates thermal expansion, reducing cracks and defects in upper layer CrAlSiN.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20501 - Materials engineering

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Corrosion Science

ISSN

0010-938X

e-ISSN

1879-0496

Svazek periodika

163

Číslo periodika v rámci svazku

February

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

22

Strana od-do

1-22

Kód UT WoS článku

000513295700038

EID výsledku v databázi Scopus

2-s2.0-85076047855