Microstructures, thermophysical properties and thermal cyclic behaviors of Nd2O3 and Sc2O3 co-doped LaMgAl11O19 thermal barrier coating deposited by plasma spraying. Issue 24 (15th December 2022)

• Record Type: Journal Article
• Authors: Lu, Xiangrong; Yuan, Jieyan; Li, Gui; Xu, Mingyi; Hu, Qing; Huang, Jingqi; Deng, Longhui; Jiang, Jianing; Dong, Shujuan; Liu, Li; Cao, Xueqiang
• Is Part Of: Ceramics international. Volume 48:Issue 24(2022)
• Page Start: 36539
• Page End: 36555
• Publication Date: 2022-12-15
• Subjects: Thermal barrier coating -- LaMgAl11O19 -- Thermophysical properties -- Mechanical properties -- Thermal cycling; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.08.214
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: In this study, La1- x Nd x MgAl11- x Sc x O19 ( x = 0.1, 0.2, 0.3; abbreviated as LNMAS-1, 2, 3) coatings which are supposed to possess better properties than LaMgAl11 O19 (LMA) were plasma-sprayed and their high-temperature performance were comparatively investigated. Results show that addition of Nd 3+ and Sc 3+ as dopants to LMA endows corresponding coatings with reduced thermal conductivity and enhanced thermal expansion coefficient, while maintaining advantageous phase stability, although still being subjected to amorphization in plasma flame and following crystallization upon high-temperature service. Furthermore, the doping could cause adherence increasing between topcoat/bondcoat, benefiting from improved melting condition, especially in LNMAS-2 and LNMAS-3 coatings, which is related to the specific powder morphology and lowered melting point. During exposure to 1350°C, mechanical performance and structure integrity of doped free-standing LNMAS coatings can be well preserved even after 400 h aging. In thermal cyclic fatigue test, LNMAS-2 and LNMAS-3 coatings undertake thermal cycling lifetime of ∼181 and 191 cycles at 1100°C, respectively, 40% durable than that of LMA coating. These preliminary results suggest that LNMAS-2, 3 might be promising candidates for advanced thermal barrier coating applications.