Effect of pack cementation temperatures on component, microstructure and anti-oxidation performance of Al-modified SiC coatings on C/C composites. Issue 6 (15th April 2020)

• Record Type: Journal Article
• Authors: Huang, Jinguo; Guo, Lingjun; Xu, Min; Zhang, Pei
• Is Part Of: Ceramics international. Volume 46:Issue 6(2020)
• Page Start: 8293
• Page End: 8298
• Publication Date: 2020-04-15
• Subjects: Carbon/carbon composites -- Coating -- Oxidation -- Pack cementation temperatures; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2019.12.059
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: SiC coatings doped with Al were synthesized on the C/C composites using the pack cementation technique. We explored the microstructure, composition, as well as anti-oxidation performance of Al-doped SiC coatings with different preparation temperatures (1500–2100 °C). The results prove that the coatings prepared at 1500–1900 °C are discontinuous 3C–SiC/2H–SiC/C/Si/Al2 O3 coatings with some holes and micro-cracks, while the coating prepared at 2100 °C is Al atoms dissolved 4H–SiC coating with inconspicuous cracks and a loose and porous surface structure. And the coating thickness and oxidation resistances are enhanced with increasing the pack cementation temperatures. Besides, the oxygen diffusion via the coating's invisible microdefects is the leading cause of the coating's oxidation produced at 2100 °C. The coating gained at 2100 °C shows the best anti-oxidation properties owing to the in situ formed Al2 O3 as well as SiO2 oxide layer on their surface.