Comparative investigation of cracking and crack-free iridium/rhenium coating on C/C composites

Rhenium (Re) coatings were prepared on C/C specimen by chemical vapor deposition (CVD) and its thermal cracks were sealed by alloying with cobalt. Then another Re coating and iridium (Ir) coating was prepared on the specimen by CVD and electrodeposition, successively. The Ir/Re coated C/C specimen was tested by oxyacetylene torch at 1800℃ for 1000s in air atmosphere. Results showed that the Ir/Re coating on the C/C composites was dense and continuous without any defects. After tested, the specimen kept integrity and no severe failure was happened. The weight loss of the specimen was just about 2.9wt.%.