二硅化钼改性硅酸镱环境障涂层的高温抗氧化行为及机理  

High-temperature Antioxidant Behavior and Mechanism of Ytterbium Silicate Environmental Barrier Coatings Modified by MoSi_(2)

作　　者：梁锐辉 钟鑫 洪督 赵芳霞[2] 牛亚然[1] 张振忠[2] 郑学斌[1] LIANG Ruihui;ZHONG Xin;HONG Du;ZHAO Fangxia;NIU Yaran;ZHANG Zhenzhong;ZHENG Xuebin(Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 200050,China;College of Materials Science and Engineering,Nanjing Tech University,Nanjing 211816,China)

机构地区：[1]中国科学院上海硅酸盐研究所,上海200050 [2]南京工业大学材料科学与工程学院,南京211816

出　　处：《热喷涂技术》2024年第1期100-108,共9页Thermal Spray Technology

基　　金：国家自然科学基金资助项目(52202075)。

摘　　要：新一代高推重比航空发动机的发展对环境障涂层(EBCs)的服役寿命和温度提出了苛刻的要求。稀土硅酸盐作为EBCs材料应用于面层,在服役过程中易产生纵向裂纹,为腐蚀性介质的侵蚀提供通道,严重影响EBCs的寿命。二硅化钼(MoSi_(2))具有优异的高温性能,有望改善稀土硅酸盐EBCs体系的高温性能。采用MoSi_(2)改性Yb_(2)SiO_(5)面层,通过真空等离子喷涂技术(VPS)分别制备了Yb_(2)SiO_(5)-XMoSi_(2)(X=0,5%和10%,体积分数)为面层,Yb_(2)Si_(2)O_(7)为中间层,Si为黏结层的三种环境障涂层体系。研究了涂层在1350℃长时间氧化前后显微结构演化过程。结果发现,掺杂MoSi_(2)涂层体系在高温氧化500 h后仍能保持结构完整且面层裂纹减少。原因在于,MoSi_(2)可消耗氧化剂,减缓涂层内部TGO的增长速率,反应产物Yb_(2)Si_(2)O_(7)与中间层成分一致,具有较好的化学相容性,有效改善了涂层体系的高温性能。The development of new generation of high thrust-to-weight ratio aero-engines places severe demands on the service life and temperature of environmental barrier coatings(EBCs).As a material for EBCs,rare-earth silicate applied to the surface layer is prone to longitudinal cracks during service,which providing channels for corrosive media to invade and seriously affecting the lifespan of EBCs.MoSi_(2)has excellent high-temperature properties and is expected to improve the high-temperature stability of rare-earth silicate EBC systems.In this work,MoSi_(2)was used to modify the Yb_(2)SiO_(5)top layer,and three types of EBC systems were prepared by vacuum plasma spraying(VPS),with Yb_(2)SiO_(5)-XMoSi_(2)(X=0,5%and 10%,volume fraction)as the top layer,Yb_(2)Si_(2)O_(7)as the intermediate layer,and Si as the bonding layer.The microstructural evolution of the coatings before and after long-term oxidation at 1350℃was studied.The results show that the MoSi_(2)-doped coating system maintains structural integrity with reduced cracks in the top layer after high-temperature oxidation for 500 h.MoSi_(2)can consume the oxidizer and slow down the growth rate of TGO inside the coating.The reaction product Yb_(2)Si_(2)O_(7)is consistent with the composition of the intermediate layer,which has better chemical compatibility and effectively improves the high-temperature performance of the coating system.

关 键 词：环境障涂层 硅酸镱 MoSi_(2) 真空等离子喷涂 高温抗氧化行为 

分 类 号：TG174.442[金属学及工艺—金属表面处理]