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Oxidation Behavior of (Mo,Hf)Si(2)-Al(2)O(3) Coating on Mo-Based Alloy at Elevated Temperature

To improve the oxidation resistance of Mo-based alloys, a novel (Mo,Hf)Si(2)-Al(2)O(3) composite coating was fabricated on a Mo-based alloy by the method of slurry sintering. The isothermal oxidation behavior of the coating was evaluated at 1400 °C. The microstructure evolution and phase composition...

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Autores principales: Lv, Yongqi, Cheng, Huichao, Geng, Zhanji, Li, Wei
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10147001/
https://www.ncbi.nlm.nih.gov/pubmed/37110050
http://dx.doi.org/10.3390/ma16083215
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author Lv, Yongqi
Cheng, Huichao
Geng, Zhanji
Li, Wei
author_facet Lv, Yongqi
Cheng, Huichao
Geng, Zhanji
Li, Wei
author_sort Lv, Yongqi
collection PubMed
description To improve the oxidation resistance of Mo-based alloys, a novel (Mo,Hf)Si(2)-Al(2)O(3) composite coating was fabricated on a Mo-based alloy by the method of slurry sintering. The isothermal oxidation behavior of the coating was evaluated at 1400 °C. The microstructure evolution and phase composition of the coating before and after oxidation exposure were characterized. The anti-oxidant mechanism for the good performance of the composite coating during high-temperature oxidation was discussed. The coating had a double-layer structure consisting of a MoSi(2) inner layer and a (Mo,Hf)Si(2)-Al(2)O(3) outer composite layer. The composite coating could offer more than 40 h of oxidation-resistant protection at 1400 °C for the Mo-based alloy, and the final weight gain rate was only 6.03 mg/cm(2) after oxidation. A SiO(2)-based oxide scale embedded with Al(2)O(3), HfO(2), mullite, and HfSiO(4) was formed on the surface of the composite coating during oxidation. The composite oxide scale exhibited high thermal stability, low oxygen permeability, and enhanced thermal mismatch between oxide and coating layers, thus improving the oxidation resistance of the coating.
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spelling pubmed-101470012023-04-29 Oxidation Behavior of (Mo,Hf)Si(2)-Al(2)O(3) Coating on Mo-Based Alloy at Elevated Temperature Lv, Yongqi Cheng, Huichao Geng, Zhanji Li, Wei Materials (Basel) Article To improve the oxidation resistance of Mo-based alloys, a novel (Mo,Hf)Si(2)-Al(2)O(3) composite coating was fabricated on a Mo-based alloy by the method of slurry sintering. The isothermal oxidation behavior of the coating was evaluated at 1400 °C. The microstructure evolution and phase composition of the coating before and after oxidation exposure were characterized. The anti-oxidant mechanism for the good performance of the composite coating during high-temperature oxidation was discussed. The coating had a double-layer structure consisting of a MoSi(2) inner layer and a (Mo,Hf)Si(2)-Al(2)O(3) outer composite layer. The composite coating could offer more than 40 h of oxidation-resistant protection at 1400 °C for the Mo-based alloy, and the final weight gain rate was only 6.03 mg/cm(2) after oxidation. A SiO(2)-based oxide scale embedded with Al(2)O(3), HfO(2), mullite, and HfSiO(4) was formed on the surface of the composite coating during oxidation. The composite oxide scale exhibited high thermal stability, low oxygen permeability, and enhanced thermal mismatch between oxide and coating layers, thus improving the oxidation resistance of the coating. MDPI 2023-04-19 /pmc/articles/PMC10147001/ /pubmed/37110050 http://dx.doi.org/10.3390/ma16083215 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Lv, Yongqi
Cheng, Huichao
Geng, Zhanji
Li, Wei
Oxidation Behavior of (Mo,Hf)Si(2)-Al(2)O(3) Coating on Mo-Based Alloy at Elevated Temperature
title Oxidation Behavior of (Mo,Hf)Si(2)-Al(2)O(3) Coating on Mo-Based Alloy at Elevated Temperature
title_full Oxidation Behavior of (Mo,Hf)Si(2)-Al(2)O(3) Coating on Mo-Based Alloy at Elevated Temperature
title_fullStr Oxidation Behavior of (Mo,Hf)Si(2)-Al(2)O(3) Coating on Mo-Based Alloy at Elevated Temperature
title_full_unstemmed Oxidation Behavior of (Mo,Hf)Si(2)-Al(2)O(3) Coating on Mo-Based Alloy at Elevated Temperature
title_short Oxidation Behavior of (Mo,Hf)Si(2)-Al(2)O(3) Coating on Mo-Based Alloy at Elevated Temperature
title_sort oxidation behavior of (mo,hf)si(2)-al(2)o(3) coating on mo-based alloy at elevated temperature
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10147001/
https://www.ncbi.nlm.nih.gov/pubmed/37110050
http://dx.doi.org/10.3390/ma16083215
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