A facile strategy for fabricating self-sealing dense coating grown in-situ on porous silicon nitride ceramics. Issue 3 (March 2021)

• Record Type: Journal Article
• Authors: Duan, Wenjiu; Jia, Dechang; Cai, Delong; Niu, Bo; Yang, Zhihua; Zhou, Yu
• Is Part Of: Journal of the European Ceramic Society. Volume 41:Issue 3(2021)
• Page Start: 2162
• Page End: 2167
• Publication Date: 2021-03
• Subjects: Porous Si3N4 -- Self-sealing method -- In-situ oxidized coating -- Mechanical properties; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2020.10.040
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: This present work explores initially the feasibility of producing in-situ surface oxidized coating on porous silicon nitride (Si3 N4 ) ceramics. Theoretical prediction identifies the applied conditions of self-sealing strategy and oxidation time required to form dense coating. Experimentally, the porous Si3 N4 ceramics with different pore structures were selected to fabricate in-situ oxidized coatings. The phase compositions, microstructures and mechanical properties of the porous Si3 N4 ceramics were investigated before and after oxidation. The results show that flat and dense coatings are prevailed in all samples, which consist of amorphous SiO2 and its precipitates besides dominant Si3 N4 phase. The strengthened substrate and strengthening effect of coating are the essential mechanisms associated with the improved mechanical properties. Self-sealing method seems to offer an inexpensive and efficient route to prepare coating on porous Si3 N4 ceramics.