无机材料学报 ›› 2022, Vol. 37 ›› Issue (12): 1267-1274.DOI: 10.15541/jim20220265

• 研究论文 • 上一篇    下一篇

硅酸镱环境障涂层抗熔盐腐蚀行为与机制研究

刘平平1,2(), 钟鑫1(), 张乐3, 李红2(), 牛亚然1, 张翔宇1, 李其连3, 郑学斌1   

  1. 1.中国科学院 上海硅酸盐研究所, 上海 200050
    2.上海大学 复合材料研究中心, 上海 200072
    3.中国航空制造技术研究院, 北京 100024
  • 收稿日期:2022-05-06 修回日期:2022-05-29 出版日期:2022-12-20 网络出版日期:2022-06-16
  • 通讯作者: 钟 鑫, 助理研究员. E-mail: zhongxin@mail.sic.ac.cn;
    李 红, 研究员. E-mail: lihong2007@shu.edu.cn
  • 作者简介:刘平平(1995-), 女, 硕士研究生. E-mail: ppliu1234@163.com
  • 基金资助:
    国家科技重大专项(2017-VI-0020-0092);上海市青年科技英才扬帆计划(19YF1453900);上海市自然科学基金(20ZR1465700)

Molten Salt Corrosion Behaviors and Mechanisms of Ytterbium Silicate Environmental Barrier Coating

LIU Pingping1,2(), ZHONG Xin1(), ZHANG Le3, LI Hong2(), NIU Yaran1, ZHANG Xiangyu1, LI Qilian3, ZHENG Xuebin1   

  1. 1. Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
    2. Research Center of Composite Materials, Shanghai University, Shanghai 200072, China
    3. Avic Manufacturing Technology Institute, Beijing 100024, China
  • Received:2022-05-06 Revised:2022-05-29 Published:2022-12-20 Online:2022-06-16
  • Contact: ZHONG Xin, assistant professor. E-mail: zhongxin@mail.sic.ac.cn;
    LI Hong, professor. E-mail: lihong2007@shu.edu.cn
  • About author:LIU Pingping (1995-), female, Master candidate. E-mail: ppliu1234@163.com
  • Supported by:
    National Science and Technology Major Project(2017-VI-0020-0092);Shanghai Sailing Program(19YF1453900);Natural Science Foundation of Shanghai(20ZR1465700)

摘要:

稀土硅酸盐环境障涂层(EBC)是应用于新一代高推重比航空发动机热端部件的重要材料, 但其在高温熔盐环境的腐蚀行为与机制尚不明晰。本工作采用真空等离子喷涂技术(VPS)制备了Yb2SiO5/Yb2Si2O7/Si环境障涂层, 并研究了该涂层体系在900 ℃、Na2SO4+25% NaCl(质量分数)熔盐环境中的腐蚀行为与机制。研究发现, 所制备的Yb2SiO5/Yb2Si2O7/Si涂层体系结构致密, 各层之间结合良好; 涂层体系腐蚀240 h, 熔盐组分渗透Yb2SiO5涂层, 在Yb2Si2O7中间层发生富集。涂层中Yb2SiO5相具有良好的稳定性, Yb2O3第二相与熔盐发生反应, 且随腐蚀时间延长, Yb2O3含量减少。中间层Yb2Si2O7相与熔盐反应生成磷灰石相NaYb9Si6O26和钠硅酸盐, 并产生Cl2和SO2等挥发性物质, 从而影响服役寿命。硅黏结层中未发现熔盐渗透现象, 保持完整。该涂层体系具有良好的抗熔盐腐蚀性能。

关键词: 环境障涂层, 硅酸镱, Na2SO4+25% NaCl熔盐, 腐蚀机制

Abstract:

Environmental barrier coating (EBC) is essential for protection of ceramic matrix composite hot-sections in future gas turbine engines with high thrust-to-weight ratio. Rare-earth silicates, such as Yb2SiO5 and Yb2Si2O7, have been developed for potential application as EBC. However, the corrosion behaviors and mechanisms of EBC in molten salt environment such as Na2SO4 at high temperature are not clear. In this work, the Yb2SiO5/Yb2Si2O7/Si coating was prepared by vacuum plasma spraying (VPS). The molten salt (Na2SO4+25% NaCl, in mass) corrosion behaviors and mechanisms of the coating at 900 ℃ for 60-240 h were investigated. Results showed that the Yb2SiO5/Yb2Si2O7/Si coating exhibited dense structure with good bonding between the triple ceramic layers. The molten salt of Na2SO4+25% NaCl penetrated the Yb2SiO5 top layer and enriched in the Yb2Si2O7 interlayer, while the interfacial bonding between the coating and substrate still remained good after corrosion for 240 h. The Yb2SiO5 phase in the top layer exhibited good stability, while the second phase of the Yb2O3 reacted with molten salt. The content of the Yb2O3 decreased with the increase of corrosion time. The Yb2Si2O7 phase in the interlayer reacted with molten salt to form apatite phase of NaYb9Si6O26 and sodium silicate as well as volatile species such as Cl2 and SO2, which might shorten the service life of the coating. Moreover, there was almost no molten salt in the silicon bond layer, which remained intact. The Yb2SiO5/Yb2Si2O7/Si coating exhibited good resistance to molten salt corrosion.

Key words: environmental barrier coating, ytterbium silicate, Na2SO4+25% NaCl molten salt, corrosion mechanism

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