Effect of PyC/Sic multi-layer coating on carbon fiber on LSIed C/C-SiC composite

Abstract

Effect of PyC/SiC multi-layer coating on carbon fiber was investigated with C/C-SiC composite that manufactured by liquid silicon infiltration(LSI). The coating layers were deposited by low pressure (2 torr) CVD method using C3H8, H2, SiH4 gases on plain woven carbon fabric and thickness of coating layer was 150/500nm (PyC/SiC). The coated fiber was not degraded during LSI process of high temperature over 2000℃ and for this reason the mechanical properties of composite was improved comparing non or single layer coated fiber. The outer SiC layer protected carbon coating layer that leads pull-out phenomenon from severe manufacturing process. The coating layer was analyzed with XPS depth profile that etch with 35nm/sec and flexural strength test was performed for mechanical properties.