摘要
To repair the damaged SiC coated C/C composites,a double-layer system including a Sm-doped boro-silicate glass external layer and a SieSiC 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 900e1200 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.
基金
This work has been supported by National Natural Science Foundations of China(grant numbers:51772247,51727804,91860203)
Creative Research Foundation of Science and Technology on Thermostructural Composite Materials Laboratory(grant number:JCKYS2019607002).
