Enhancing anti-oxidation and thermal-radiation performance of the repaired borosilicate glass coating on C/C composites by Sm-doping

• Published in: Journal of Materiomics Vol. 8; no. 2; pp. 417 - 426
• Main Authors: Wang, Han-Hui, Teng, Liu, Kong, Jing-An, Liu, Xue-Song, Shi, Xiao-Hong, Li, He-Jun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2022; Elsevier
• Subjects: Coating repair; Laser cladding; Oxidation resistance; Rare earth; Thermal radiation; Oxidation resistance; Thermal radiation; Rare earth; Laser cladding; Coating repair
• ISSN: 2352-8478
• DOI: 10.1016/j.jmat.2021.07.005

To repair the damaged SiC coated C/C composites, a double-layer system including a Sm-doped borosilicate glass external layer and a SiSiC inner layer was prepared by a slurry-based laser cladding technique. Isothermal oxidation experiment and indirect/direct thermal-radiation measurements were performed. The results showed that the absorbance of borosilicate glass to the laser at 900–1200 nm was improved significantly by Sm-doping. Consequently, the repaired coating with a more compact structure and better oxidation resistance was obtained. After oxidation at 1773 K for 10 h, the mass loss of the damaged sample could be reduced by 74.98% with repairing. By increasing laser-absorption and reducing viscosity, the thermal-radiation property of the repaired coating was enhanced to decrease the surface temperature greatly. A repair system with excellent thermal protection performance was achieved. [Display omitted] •A double-layer repair system was designed for the damaged SiC coated C/C composites.•Laser cladding technique was used to repair the damaged SiC coating on C/C substrates.•The laser-absorption of borosilicate glass could be improved significantly by Sm-doping.•The viscosity of borosilicate glass could be decreased slightly by Sm-doping.•The anti-oxidation and thermal-radiation properties of the repaired sample were studied.