无机材料学报 ›› 2019, Vol. 34 ›› Issue (9): 938-946.DOI: 10.15541/jim20180529

• 研究论文 • 上一篇    下一篇

镀铝改性对PS-PVD 7YSZ热障涂层抗CMAS腐蚀影响机制

范佳锋1,2,张小锋1,2(),周克崧1,2(),刘敏2,邓畅光2,邓春明2,牛少鹏2,邓子谦2   

  1. 1.广东工业大学 材料与能源学院, 广州 510006
    2.广东省新材料研究所 现代材料表面工程技术国家工程实验室, 广东省现代表面工程技术重点实验室, 广州 510650
  • 收稿日期:2018-11-09 修回日期:2019-01-11 出版日期:2019-09-20 网络出版日期:2019-05-22
  • 作者简介:范佳锋(1998-), 男, 硕士研究生. E-mail: 1577619201@qq.com
  • 基金资助:
    国家自然科技基金(51801034);国家自然科技基金(51771059);广东省自然科学基金(2017A030310315);广东省自然科学基金(2016A030312015);广州市及广东省项目(201707010455);广州市及广东省项目(2018GDASCX-0950);广州市及广东省项目(2017A070701027)

Influence of Al-modification on CMAS Corrosion Resistance of PS-PVD 7YSZ Thermal Barrier Coatings

FAN Jia-Feng1,2,ZHANG Xiao-Feng1,2(),ZHOU Ke-Song1,2(),LIU Min2,DENG Chang-Guang2,DENG Chun-Ming2,NIU Shao-Peng2,DENG Zi-Qian2   

  1. 1.School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China
    2.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
  • Received:2018-11-09 Revised:2019-01-11 Published:2019-09-20 Online:2019-05-22
  • Supported by:
    National Natural Science Foundation of China(51801034);National Natural Science Foundation of China(51771059);Guangdong Natural Science Foundation(2017A030310315);Guangdong Natural Science Foundation(2016A030312015);Guangzhou City & Guangdong Province Project(201707010455);Guangzhou City & Guangdong Province Project(2018GDASCX-0950);Guangzhou City & Guangdong Province Project(2017A070701027)

摘要:

采用等离子喷涂-物理气相沉积(PS-PVD)方法制备了羽毛柱状结构7YSZ (氧化钇稳定氧化锆, 简称YSZ)热障涂层, 并对涂层进行了表面镀铝改性研究。在1050 ℃保温5 min、空冷5 min为一个热循环的条件下, 测试了改性前后热障涂层的热循环性能。此外, 在1200 ℃高温下对涂层进行了CMAS (CaO、MgO、Al2O3、SiO2等硅酸铝盐物质的简称)腐蚀实验。采用扫描电子显微镜(SEM)、能谱仪(EDS)和X射线衍射仪(XRD)对涂层显微组织、元素分布及物相组成进行了表征。通过研究喷涂态涂层与镀铝改性涂层的CMAS腐蚀行为, 分析了涂层腐蚀机制, 并阐述了镀铝改性对涂层耐腐蚀的作用机理。结果表明: 镀铝改性后的涂层保持较好的热稳定性, 经过5200次热循环后未见涂层剥落。喷涂态涂层受CMAS腐蚀后, 产生了“波浪”状形变, CMAS完全渗透了7YSZ涂层; 而镀铝改性涂层, 由于通过Al与ZrO2原位反应, 在涂层表面形成有耐腐蚀的α-Al2O3致密层, 涂层腐蚀情况得到了显著改善。研究发现, α-Al2O3致密层不仅对涂层形成机械保护, 还影响CMAS在涂层上的热化学反应, 使得CaO、Al2O3、SiO2三种氧化物在涂层上的渗入受到抑制, 但MgO在涂层中的渗透未受到明显影响。此外, 本文还建立了以菲克第二定律为核心的数学模型, 以评估镀铝改性技术对涂层耐CMAS腐蚀能力的影响。

关键词: 等离子喷涂-物理气相沉积, 7YSZ, 镀铝改性, CMAS腐蚀

Abstract:

7YSZ thermal barrier coatings with feather-like columnar structure were prepared by plasma spray-physical vapor deposition (PS-PVD), and were carried out with Al-modification. After that, the as-sprayed and Al-modified 7YSZ TBCs were conducted with thermal cycling, heated at 1050 ℃ for 5 min and air-cooling for 5 min, respectively. And the CMAS corrosion tests were carried out at 1200 ℃. Microstructure, element and phase composition of the coating were analyzed by SEM, EDS and XRD. Corrosion mechanism of CMAS and the corrosion resistance mechanism of Al-modified coating were investigated. The results showed that the Al-modified coatings kept good thermal stability. And the coating had no apparent spallation, after 5200 thermal cycles. The as-sprayed coating was destroyed by CMAS, and "wave" deformation was observed. The 7YSZ coating was completely permeated by CMAS. Dense corrosion-resistant layer of α-Al2O3 was formed on the surface of the coating by Al-modification, and the corrosion of the coating was significantly improved. It was found that α-Al2O3 layer not only protected the coating by separating CMAS, but also had positive effect on the thermochemical reaction in CMAS corrosion. Due to formation of α-Al2O3 layer, the oxides of CaO, Al2O3 and SiO2 were hard to penetrate the coating. However, the penetration of MgO was not significantly affected by Al-modification. In addition, a mathematical model based on Fick's second law was established to evaluate the effect of Al-modification on the CMAS corrosion resistance of 7YSZ coatings.

Key words: plasma spray-physical vapor deposition, 7YSZ, Al-modification, CMAS corrosion

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