文章信息/Info

Title:

Al-modified environmental barrier coating prepared by atmospheric plasma spray

作者:

張小鋒1; 周克崧1; 劉敏1; 李洪1; 陽海棠2; 牛少鵬1; 鄧春明1; 鄧暢光1

1. 現代材料表面工程技術國家工程實驗室及廣東省現代表面工程技術重點實驗室，廣東省新材料研究所 廣州 510650； 2. 航空航天學院，中南大學 長沙410083）

Author(s):

ZHANG Xiaofeng1;  ZHOU Kesong1;  LIU Min1;  LI Hong1;  YANG Haitang2;  NIU Shaopeng1;  DENG Chunming1;  DENG Changguang1

1. National Engineering Laboratory for Modern Materials Surface Engineering Technology & The Key Lab of Guangdong for Modern Surface Engineering Technology，Guangdong Institute of New Materials, Guangzhou 510650, China; 2. Hunan Laboratory of Advanced Fibers and Composites, Central South University, Changsha 410083, China

關鍵詞:

環境障涂層; 大氣等離子噴涂; 鍍鋁改性; 水氧腐蝕; CMAS腐蝕; 熱循環

Keywords:

EBCS;  atmospheric plasma spray;  Al-modification;  water-oxygen corrosion;  CMAS corrosion;  thermal cycle

DOI:

10.7502/j.issn.1674-3962.2018.12.04

文獻標志碼:

A

摘要:

陶瓷基復合材料(CMC)由于具有較低的密度(高溫合金的1/3～1/4)、較高的服役溫度(比高溫合金高200～240 ℃)以及良好的結構強度(高溫合金的2倍)，已成為未來大推重比航空發動機熱端部件的首選材料。發動機服役過程中，熱端部件完全暴露于空氣氣氛中，服役環境惡劣，以SiC/SiC為代表的CMC部件直接面臨著腐蝕、燒蝕、沖刷等問題，因此急需開展一類高性能CMC熱防護涂層即環境障涂層（EBCs）的研究。通過大氣等離子噴涂在SiC/SiC CMC基體表面制備硅/莫來石/硅酸鐿（Yb2SiO5）三層結構EBCs。為提高EBCs服役性能，對涂層樣品進行鍍Al表面改性即采用磁控濺射技術在涂層表面鍍Al全包覆，然后對其進行真空熱處理。在高溫低真空下，涂層表面Al膜發生熔融并在毛細管力的作用下往多孔涂層內部滲透并與Yb2SiO5發生原位反應，在涂層表面形成一層致密α�睞l2O3層。對噴涂態及鍍Al表面改性涂層進行典型模擬服役環境性能對比實驗，發現鍍Al表面改性EBCs具有較好的抗高溫水氧及耐CMAS(CaO-MgO-Al2O3-SiO2)腐蝕性能。另外，通過實驗觀察，原位形成的α-Al2O3致密層對涂層的熱循環性能無明顯影響。

Abstract:

The ceramic matrix composite (CMC) material with low density (1/3～1/4 of superalloy) and high operation temperature (200～240℃>superalloy), it has been became a preferred material in future for high thrust-weight ratio aero-engine. In service operation, hot components are completely exposed to atmospheric environment. Representative CMC component of SiC/SiC faces serious operation conditions such as corrosion, ablation, erosion, etc. Therefore, it is urgent to develop a high performance protective coating for CMC component (i.e. environment barrier coatings, EBCs). In this investigation, three-layer-structured EBCs (Si/mullite/Yb2SiO5) were prepared by atmospheric plasma spray. For improving the performances of EBCs, the EBCs samples were deposited with Al film and carried out with vacuum heat treatment. Through in-situ synthesis between Al and Yb2SiO5 at high temperature in vacuum, a dense α-Al2O3 overlay can be formed. The results show that the Al-modified EBCs samples have better oxygen-water, CMAS corrosion resistance than the as-sprayed EBCs. Besides, Al-modification for EBCs have no apparent negative affection on thermal cycle performance compared with the as-sprayed EBCs.