文章信息/Info

Title:

Thermal Cycling Resistance of Aluminum-Infiltration-Densified Environmental Barrier Coatings

文章編號:

1674-3962(2025)02-0125-09

作者:

魏曉薇; 董琳; 張小鋒; 楊冠軍

1. 西安交通大學 金屬材料強度國家重點實驗室，陜西 西安 710049 2. 廣東省科學院 新材料研究所，廣東 廣州 510650

Author(s):

WEI Xiaowei;  DONG Lin;  ZHANG Xiaofeng;  YANG Guanjun

1.State Key Laboratory for Mechanical Behavior of Materials, Xi‘an Jiaotong University, Xi’an 710049, China 2. Institute of New Materials, Guangdong Academy of Science, Guangzhou 510650, China

關鍵詞:

環境障涂層（EBCs）; 致密化; 熔滲; 縱向裂紋; 抗熱循環性能

Keywords:

environmental barrier coatings (EBCs); densification; infiltration; vertical crack; thermal cycling resistance

分類號:

TG174.4;V263

DOI:

10.7502/j.issn.1674-3962.202409005

文獻標志碼:

A

摘要:

環境障涂層（environmental barrier coatings，EBCs）是碳化硅纖維增強碳化硅陶瓷基復合材料（SiCf/SiC CMCs）在航空發動機熱端部件應用的關鍵，但在制備過程中EBCs難以避免地產生表面裂紋及孔隙，成為發動機環境水氧等腐蝕介質的快速擴散通道，因此，制備致密的EBCs是提高SiCf/SiC復合材料抗腐蝕性能的關鍵。此外，為保證高低溫循環服役條件下的持久性，EBCs需具備優異的抗熱循環性能。采用熔滲鋁封孔的方法獲得致密化EBCs，研究了涂層在1050 ℃~室溫熱循環條件下的結構演變規律，揭示了致密化處理對涂層抗熱循環性能的影響機制。結果表明，熔滲鋁封孔法消除了噴涂態EBCs的表面裸露孔隙，并在表面形成鐿鋁石榴石（YbAG）原位反應層；在熱循環過程中，噴涂態涂層內應力逐漸累積，致使縱向裂紋數量增多，裂紋間距減小；熔滲鋁時的熱處理過程顯著提高了EBCs內應力，促使裂紋早期生長和擴展，裂紋數量和間距與噴涂態EBCs熱循環200次后的相當，且在熱循環過程中裂紋未新增和擴展。本研究為耐熱循環熔滲鋁致密化EBCs的制備提供了實驗數據支撐。

Abstract:

Environmental barrier coatings (EBCs) are crucial for the application of silicon carbide fiber-reinforced silicon carbide ceramic matrix composites (SiCf/SiC CMCs) in hot end components of aircraft engines. However, during the coating preparation process, it is difficult to avoid surface cracks and pores, which become rapid diffusion channel for corrosive media such as water and oxygen in the engine environment. Therefore, preparing densified EBCs is the key to improve SiCf/SiC CMCs corrosion resistance. Additionally, to ensure durability under cycling conditions with the high and low temperature changes,distinguished thermal cycling resistance is essential for EBCs. This study used the method of aluminum-infiltration to obtain densified EBCs, and investigated the structural evolution of the coating under 1050 ℃~room temperature thermal cycling, revealing the influence mechanism of densification treatment on the thermal cycling resistance of the coating. The results indicated that the aluminum-infiltration-densified method eliminated the surface exposed pores of the sprayed EBCs and formed an in-situ reaction layer of ytterbium aluminum garnet (YbAG) on the surface. During the thermal cycling process, the internal stress of the sprayed EBCs gradually accumulated, resulting in an increase in the number of vertical cracks and a decrease in crack spacing. The heat treatment of aluminum-infiltration process significantly increased the internal stress of EBCs, promoting early crack growth and propagation, the number and spacing of cracks were comparable to those of sprayed EBCs after 200 thermal cycles, and no new or extended cracks were observed during the thermal cycling. Therefore, this study provides experiment data support for the preparation of thermal cycling resistant aluminum�瞚nfiltration-densified EBCs.