Deposition and characterization of thermal barrier coatings of ZrO2–4mol.% Y2O3–1mol.% Gd2O3–1mol.% Yb2O3

• Published in: Surface & coatings technology 2015-04, Vol.268, p.205-208
• Main Authors: Bobzin, Kirsten, Zhao, Lidong, Öte, Mehmet, Linke, Thomas Frederik
• Format: Article
• Language: English
• Subjects: Coatings; Deposition; High energy ball milling; Microstructure; Multicomponent oxide-doped zirconia; Thermal barrier coating; Thermal barrier coatings; Thermal conductivity; Thermal properties; Thermal shock; Thermal shock behavior; Zirconium dioxide
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2014.05.051

Multicomponent oxide-doped zirconia based thermal barrier coatings (TBCs) have been found to possess significantly lower thermal conductivity and better sintering resistance at high temperatures than current state of the art ZrO2–(7–8)wt.% Y2O3 TBCs. In this study, two TBC systems of multicomponent oxide-doped zirconia (ZrO2–4mol.% Y2O3–1mol.% Gd2O3–1mol.% Yb2O3) were produced with a three-cathode plasma generator TriplexPro-210. The first TBC system was deposited using a conventional fused and crushed spray powder. This powder was further processed by high energy ball milling to get a highly porous second TBC system. The two TBC systems were characterized in terms of their microstructures, phase compositions, mechanical properties and thermo-physical properties. Their thermal shock behavior was evaluated using thermal cyclic tests at 1150°C. The results showed that the second TBC system had a significantly lower thermal diffusivity and better thermal shock behavior compared to the first TBC system due to its highly porous microstructure. •TBC systems of ZrO2–4mol.% Y2O3–1mol.% Gd2O3–1mol.% Yb2O3 were produced.•A highly porous microstructure with a porosity of 34% was realized.•This microstructure led to a lower thermal diffusivity than a conventional TBC.•It resulted in a better thermal shock behavior than the conventional TBC.