Research on Thermal Stability and Properties of Ca₃ZrSi₂O₉ as Potential T/EBC Materials

• Main Authors: Yangyang Pan, Bo Liang, Yaran Niu, Dijuan Han, Dongdong Liu, Xuebin Zheng
• Format: Article
• Language: English
• Published: MDPI AG 2021-05-01
• Series: Coatings
• Subjects: Ca₃ZrSi₂O₉ coating; thermal stability; thermal property; mechanical property; atmospheric plasma spray
• Online Access: https://www.mdpi.com/2079-6412/11/5/583

In this study, a new coating material for thermal barrier coating (TBC) or environment barrier coating (EBC) application, Ca₃ZrSi₂O₉ (CZSO), was synthesized and prepared by atmospheric plasma spray (APS) technology. The evolution of the phases and microstructures of the coatings with different thermal-aged were characterized by XRD, XRF, EDS and SEM, respectively. The thermal stability was measured by TG-DTA and DSC. The mechanical and thermal properties, including Vickers hardness (H_V), fracture toughness (K_IC), thermal conductivity (κ) and coefficient of thermal expansion (CTE) were focused on. It was found that the as-sprayed CZSO coating contained amorphous phase. Crystalline transformation happened at 900–960 °C and no mass changes took place from room temperature (RT) to 1300 °C. The phenomena of microcrack self-healing and composition uniformity were observed during thermal aging. The κ of coating was very low at about 0.57–0.80 W·m⁻¹·K⁻¹ in 200–1200 °C. The combined properties indicated that the CZSO coating might be a potential T/EBC material.