Study of toughening behavior of SiC whiskers on 8YSZ thermal barrier coatings

• Published in: Surface & coatings technology Vol. 455; p. 129232
• Main Authors: Liu, Dianchao, Jing, Yongzhi, Cui, Xiufang, Jin, Guo, Chen, Zhuo, Wang, Xinhe, Liu, Anying, Li, Qicheng, Tian, Haoliang, Fang, Yongchao
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.02.2023
• Subjects: Bending strength; Fracture toughness; SiC whiskers; Thermal barrier coatings; Tribological properties; Bending strength; Thermal barrier coatings; SiC whiskers; Tribological properties; Fracture toughness
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2023.129232

The embrittlement of thermal barrier coatings (TBCs) in a high-temperature service environment inhibits the ability of the top-coat to resist crack initiation and propagation, in which the cracks are generated by erosion or wear of particles, limiting the service durability of TBCs. This study was based on the preparation of SiC whiskers (SiCw) / Y2O3 partially stabilized ZrO2 (YSZ) integrated composite powder, and the SiCw/YSZ composite TBCs was prepared through the atmospheric plasma spraying (APS) to improve the toughness of the top-coat. The effects of SiCw on the fracture toughness, tribological properties, erosion resistance and bending strength of the coatings were studied. The results showed that the fracture toughness of the composite coating with a SiCw length-to-diameter ratio (L/D ratio) of 250 was 24.6 % higher than the YSZ coating. Moreover, the composite coating presented excellent performance in wear, erosion, and resistance to crack propagation and spallation. The low amplitude of the Weibull modulus m of hardness distribution of the doped coating proved the stability effect of SiCw on the reinforcement and toughening of the coating. •A SiC whiskers/Y2O3 partially stabilized ZrO2 (YSZ) composite coating was successfully deposited.•The toughening mechanism of SiC whiskers in thermal barrier coatings (TBCs) was revealed.•SiC whiskers can significantly improve the wear resistance and bending strength of TBCs.•Promote the application process of SiC whiskers toughened TBCs under extreme service environments.