Effect of residual silicon on the oxidation resistance of bilayer Yb2Si2O7/SiC coated C/SiC composites at high temperature. (1st July 2020)

• Record Type: Journal Article
• Authors: Chen, Pengju; Xiao, Peng; Li, Zhuan; Li, Jinwei; Pu, Dongmei; Deng, Pingyi; Li, Yang
• Is Part Of: Corrosion science. Volume 170(2020)
• Publication Date: 2020-07-01
• Subjects: LSI -- C/SiC composites -- Residual silicon -- Oxidation; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2020.108676
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: LSI C/SiC composites without residual silicon was prepared by embedded methods. A bilayer Yb2 Si2 O7 /SiC coating was fabricated on C/SiC composites by CVD and sol-gel method combined with air spraying. Residual silicon overflowed from C/SiC composites matrix and damaged the oxidation resistance of Yb2Si2O7/SiC coating at 1773 K. Residual silicon improved the oxidation resistance of Yb2 Si2 O7 /SiC coating at 1673 K. The study provides guidance for higher-temperature application of LSI C/SiC composites. Abstract: The influence of residual silicon in C/SiC composites on oxidation resistance of bilayer Yb2 Si2 O7 /SiC coating in ambient air were investigated. Results indicated that new micro-crack caused by overflow of residual silicon from matrix in C/SiC composites is detrimental to the oxidation resistance of Yb2 Si2 O7 /SiC coating at 1773 K. However, oxidation resistance of the bilayer coating at 1673 K can be improved because the SiO2 film induced by oxidation of residual silicon can self-heal micro-cracks in C/SiC composites. After removing residual silicon in C/SiC composites, the bilayer Yb2 Si2 O7 /SiC coating has good oxidation resistance for C/SiC composites matrix at 1673 K and 1773 K.