J. Mater. Sci. Technol. ›› 2016, Vol. 32 ›› Issue (1): 28-33.DOI: 10.1016/j.jmst.2015.11.022

• Orginal Article • Previous Articles     Next Articles

Improved Toughness and Thermal Expansion of Non-stoichiometry Gd2 - xZr2 + xO7 + x/2 Ceramics for Thermal Barrier Coating Application

Lei Guo1, 2, 3, Mingzhu Li1, 2, Yu Zhang1, 2, Fuxing Ye1, 2, 3   

  1. 1 School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China;
    2 Tianjin Key Laboratory of Advanced Joining Technology, Tianjin University, Tianjin 300072, China;
    3 Key Lab of Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Tianjin 300072, China
  • Received:2015-10-16 Revised:2015-11-02 Online:2016-01-19
  • Supported by:
    This work is sponsored by the National Natural Science Foundation of China (Grant Nos.51501127 and 51375332) and the Specialized Research Fund for the Doctoral Program of Higher Education (No. 20120032110031).

Abstract: Gd2Zr2O7 has been considered as a promising thermal barrier coating candidate, but its toughness and thermal expansion coefficient (TEC) need to be improved. In this study, Gd2 - xZr2 + xO7 + x/2 (x = 0, 0.1, 0.3, 0.5, 0.7) compounds were produced to improve the toughness and enlarge the TEC. Gd2Zr2O7 and Gd1.9Zr2.1O7.05 exhibited pyrochlore structure, while Gd2 - xZr2 + xO7 + x/2 (x = 0.3, 0.5, 0.7) consisted of pyrochlore and t'-ZrO2phases. With increasing ZrO2 content, the pyrochlore in the compounds had decreased lattice parameter, and its ordering degree decreased when x ≤ 0.3, then it almost kept unchanged with higher ZrO2 content. Among the Gd2 - xZr2 + xO7 + x/2 ceramics investigated, the toughness of the compounds increased with increasing ZrO2 content, while Gd1.7Zr2.3O7.15 exhibited the largest TEC. The related mechanisms were discussed in detail.

Key words: Thermal barrier coating, Ceramic, Phase structure, Toughness, Thermal expansion coefficient