The toughening design of multi-layer antioxidation coating on C/C matrix via SiC-SiCw transition layer grown in-situ

• Published in: Journal of the European Ceramic Society 2022-01, Vol.42 (1), p.43-51
• Main Authors: Xie, Chen, Song, Shaolei, He, Guanzhong, Mao, Zhihui, Ma, Cuncheng, Zhang, Tong, Hu, Pengfei, Zhen, Qiang
• Format: Article
• Language: English
• Subjects: C/C composites; Composite coating; High temperature oxidation resistance; Self-healing; SiC whisker
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2021.09.043

Poor antioxidant and thermal-shock capacities of C/C composites thermal barrier coating (TBC) caused by cracking and shedding of coatings has been a major obstacle blocking the development of C/C composites. Herein, in-situ growth of whisker reinforced silicon carbide transition layer and inter-embedding mechanism of multi-gradient coatings were brought into the design of TBC to enhance the antioxidant and thermal-shock capacities. A three-layer gradient coating SiC-SiCw/ZrB2-SiC/ZrSiO4-aluminosilicate glass (ZAG) from inside to outside, in which ZrB2-SiC/ZAG serve as oxygen barrier layers with self-healing ability and SiC-SiCw provides thermal stress buffering and bonding against cracking and shedding of coatings, is designed. The ZAG mainly forms a dense oxygen blocking frontier with self-healing ability through fluidized glass, while the ZrB2-SiC can react actively with infiltrated oxygen in a way of self-sacrifice, preventing oxygen erosion to C/C matrix and SiC-SiCw transition layer. As a result, the collaborative work among layers endows this coating with excellent high temperature service performance. This work provides a new insight for the design of excellent TBC.