文章信息/Info

Title:

Oxidation Behavior in Wet Oxygen Environment of Y2O3 Modified SiC Ceramics

文章編號:

1674-3962(2023)06-0456-08

作者:

張俊敏1; 2; 3;  陳小武1; 2;  楊金山1; 2;  張翔宇1; 2;  闞艷梅1; 2; 廖春景1; 2;  胡建寶1; 2;  周海軍1; 2;  董紹明1; 2

1. 中國科學院上海硅酸鹽研究所 高性能陶瓷與超微結構國家重點實驗室, 上海 200050 2. 中國科學院上海硅酸鹽研究所 結構陶瓷及復合材料工程研究中心, 上海 200050 3. 上海科技大學物質科學與技術學院, 上海 200031

Author(s):

ZHANG Junmin1; 2; 3;  CHEN Xiaowu1; 2;  YANG Jinshan1; 2;  ZHANG Xiangyu1; 2;  KAN Yanmei1; 2;  LIAO Chunjing1; 2;  HU Jianbao1; 2; ZHOU Haijun1; 2;  DONG Shaoming1; 2

1. State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China 2. Structural Ceramics and Composites Engineering Research Center, Shanghai Institute of Ceramics,Chinese Academy of Sciences, Shanghai 200050, China 3. School of Physical Science and Technology,ShanghaiTech University,Shanghai 200031, China

關鍵詞:

SiC 陶瓷;  高溫水氧環境;  水氧行為;  耐水氧侵蝕機理;  連續Y2 Si2 O7 層

Keywords:

SiC ceramics;  high-temperature wet oxygen environment;  wet-oxidation behavior;  wet-oxidation resistance mechanism;  continuous Y2Si2O7 layer

分類號:

TB332; V23

DOI:

10.7502/j.issn.1674-3962.202209013

文獻標志碼:

A

摘要:

連續碳化硅纖維增強碳化硅陶瓷基復合材料(SiCf / SiC)因高溫水氧侵蝕致使力學性能急劇下降, 限制了其熱端部件在航空發動機中的長壽命服役。研究證實, 該侵蝕主要表現為SiC 基體和纖維與水、氧氣反應生成氣相Si(OH)4 , 導致質量耗散。因此, 從組分、結構調控角度提升SiC 耐水氧侵蝕性能已成為研究熱點。對比研究了添加和未添加Y2 O3 對SiC 陶瓷水氧侵蝕行為的影響。與SiC 陶瓷相比, SiC-Y2 O3 陶瓷的氧化速率及揮發速率均明顯下降, 且隨著氧化溫度的升高, 兩者差距愈發明顯, 可見添加Y2 O3 后SiC 陶瓷的耐水氧侵蝕性能得到明顯改善。氧化后的陶瓷微觀結構表明, SiC-Y2 O3 陶瓷氧化層明顯更薄且更致密, 進一步分析表明這主要由Y 組分在陶瓷表面的遷移以及聚集所致。在侵蝕過程中, 陶瓷內部的Y2 O3 會 向SiC 陶瓷表面遷移, 并與SiO2 反應形成β-Y2 Si2 O7 , 并逐漸聚集形成連續的Y2 Si2 O7 層。因此, 在氧化層與SiC 陶瓷交界處形成了一個富Y2 Si2 O7 / 富Y2 O3層。多層含Y 氧化層在陶瓷表面形成水氧阻擋屏障, 有效抑制了水氧介質向陶瓷內部的滲透與侵蝕。該研究結果為SiCf / SiC 復合材料的耐水氧結構設計與調控提供了重要思路。

Abstract:

The mechanical properties of continuous silicon carbide fiber reinforced silicon carbide matrix composites(SiCf / SiC) decrease rapidly under high-temperature wet oxygen environment due to the corrosion from wet oxygen,which limits the long-life service of the hot end components in aero-engines. It is confirmed that the corrosion of SiC generates gas phase Si(OH)4, which leads to mass dissipation.Therefore, it has been a research hotpot that how to improve the wet-oxidation resistance in terms of composition and structure regulation. This paper contrasted the oxidation behaviors of SiC ceramics with and without Y2O3 addition under wet oxygen environment. Compared with SiC ceramics, the oxidation rates and the volatilization rates of SiC-Y2O3 ceramics decrease significantly and the difference between the two becomes more obvious with the increase of oxidation temperature. It can be seen that the wet-oxidation resistance of SiC ceramics is improved dramatically by adding Y2O3. The microstructures analyses show that the oxide layer of SiC-Y2O3 ceramics is thinner and denser. The further analyses indicate that these results from the migration and aggregation of Y-contained phase towards the surface of SiC-Y2O3 ceramics. During the oxidation process, the Y2O3 in the ceramic can migrate to the surface and react with SiO2 to form β-Y2Si2O7. Finally, the β-Y2Si2O7 aggregates on the surface of the oxide layer to form a continuous β-Y2Si2O7 layer. Therefore, a Y2Si2O7 / Y2O3-rich layer is formed at the junction of the oxide layer and the ceramic matrix.The multilayer Y-contained layers can inhibit the corrosion of wet oxygen spreading to the inner matrix. This study provides important ideas for the design and regulation of wet-oxidation resistant SiCf / SiC composites.