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Different compositions of yttrium silicates coatings were deposited on SiC-C/C by plasma spraying and an outer borosilicate glass was applied on the yttrium silicates coatings surfaces.The structure of the multi-layer coatings was characterized by XRD and SEM analyses.High temperature oxidation behavior of the multi-layer coatings coated C/C composites was investigated.Results show that SiC/2SiO2 Y2O3/1.5SiO2Y2O3/SiO2 Y2O3/glass multi-layer coating has better high temperature oxidation resistance,protecting carbon/carbon composites from oxidation at 1 773 K in air for 164 h with the weight loss of 1.65%.The oxidation weight loss of the coated C/C with time accorded with parabolic rule in the temperature range 1 573 K-1 873 K;and the corresponding oxidation activation energy of the coated carbon/carbon composites is 132.2 kJ/mol.