J. Mater. Sci. Technol. ›› 2011, Vol. 27 ›› Issue (5): 408-414.

• Reviews • 上一篇    下一篇

Influence of Re on the properties of NiCoCrAlY coating alloys

梁静静1,韦华2,朱银莲2,孙晓峰1,胡壮麒3   

  1. 1. 中国科学院金属研究所
    2. 金属所
    3. 中国科学院金属研究所高温合金部
  • 收稿日期:2010-06-09 修回日期:2010-11-15 出版日期:2011-05-28 发布日期:2011-05-28
  • 通讯作者: 梁静静
  • 基金资助:

    国家重点基础研究发展计划;National Natural Science Foundation of China

Influence of Re on the Properties of a NiCoCrAlY Coating Alloy

J.J. Liang1,2), H. Wei1,3), Y.L. Zhu1), X.F. Sun1), Z.Q. Hu1), M.S. Dargusch3), X.D. Yao3)   

  1. 1) Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
    2) Graduate School of Chinese Academy of Sciences, Beijing 100039, China
    3) School of Materials & Mining Engineering, The University of Queensland, QLD 4072, Australia
  • Received:2010-06-09 Revised:2010-11-15 Online:2011-05-28 Published:2011-05-28
  • Contact: J.J. Liang
  • Supported by:

    the National Basic Research Program (``973 Program") of China under grant No. 2010CB631200 (2010CB631206), the National Natural Science Foundation of China (NSFC) under grant Nos. 50931004, 51071164, U1037601 and 50671102, and the opening fund of State Key Laboratory of Nonlinear
    Mechanics (LNM), Institute of Mechanics, Chinese Academy of Sciences.

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摘要： MCrAlY can serve as stand-alone overlay coatings or bond coats in thermal barrier coating systems, and its properties play a vital role in determining the performance of these coating systems. In order to further understand the behavior of MCrAlY coatings, several NiCoCrAlY model alloys with different levels of Re (0, 3wt.%, 6wt.%, and 9wt.%) were investigated. Microstructural observation showed the addition of Re promoted the precipitation of Cr-rich phases, such as ?-Cr and ?. The presence of ?-Cr lowered the coefficient of thermal expansion (CTE) of the coating alloys, which could reduce the CTE mismatch at the scale-metal interface. The solid solution strengthening effect of Re is responsible for an increase in Rockwell hardness of the coating alloys. But the isothermal oxidation resistance at 1100oC was deteriorated due to the precipitation of brittle ?-Cr phase, a phase of inferior oxidation resistance compared with ?-NiAl and ?-Ni.

Abstract: MCrAlY can serve as stand-alone overlay coatings or bond coats in thermal barrier coating systems, and its properties play a vital role in determining the performance of these coating systems. In order to further understand the behavior of MCrAlY coatings, several NiCoCrAlY model alloys with different levels of Re (0.3 wt%, 6 wt%, and 9 wt%) were investigated. Microstructural observation showed the addition of Re promoted the precipitation of Cr-rich phases, such as α-Cr and σ. The presence of α-Cr lowered the coefficient of thermal expansion (CTE) of the coating alloys, which could reduce the CTE mismatch at the scale-metal interface. The solid solution strengthening effect of Re is responsible for an increase in Rockwell hardness of the coating alloys. But the isothermal oxidation resistance at 1100°C was deteriorated due to the precipitation of brittle α-Cr phase, a phase of inferior oxidation resistance compared with β-NiAl and γ-Ni.

Key words: NiCoCrAlY, Phase constitution, Oxidation, Thermal expansion behavior, Hardness