Thermal and mechanical properties of Ta2O5 doped La2Ce2O7 thermal barrier coatings prepared by atmospheric plasma spraying. Issue 7 (July 2019)

• Record Type: Journal Article
• Authors: Zhang, Hao; Sun, Junbin; Duo, Shuwang; Zhou, Xin; Yuan, Jieyan; Dong, Shujuan; Yang, Xiong; Zeng, Jinyan; Jiang, Jianing; Deng, Longhui; Cao, Xueqiang
• Is Part Of: Journal of the European Ceramic Society. Volume 39:Issue 7(2019)
• Page Start: 2379
• Page End: 2388
• Publication Date: 2019-07
• Subjects: La2Ce2O7 -- Ta2O5 doping -- Thermal conductivity -- Failure mechanism; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2019.02.041
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: La2 Ce2 O7 (LC) is a new promising thermal barrier coating (TBC) material for high-temperature applications. However, the sudden decrease of thermal expansion coefficient (TEC) at ∼623 K limits its application. In this study, the plasma-sprayed La2 Ce1.7 Ta0.3 O7.15 (LCT) coating was developed by partial substitution of Ce 4+ in LC with Ta 5+ . LCT coating shows lower thermal conductivity between 298 K and 1273 K (0.54–0.71 W/(m·K)) than LC coating (0.65–0.85 W/(m·K)) and the traditional yttria partially stabilized zirconia (YSZ) coating (1.53–1.72 W/(m·K)). It also exhibits excellent thermal stability at least up to 1573 K for 1000 h. What is more, the sudden TEC drop is suppressed owing to the reduced oxygen vacancy concentration governed by Ta 5+ -substitution content. As a result, LCT TBC shows an improved thermal cycling lifetime in an air furnace as compared to LC TBC.