PRELIMINARY-STUDY OF IRIDIUM COATING ON CARBON-CARBON COMPOSITES

Iridium coating was deposited on as-received, polished and chemical va pour deposited (CVD) pyro carbon-coated carbon/carbon composite by d.c . sputtering. The as-received surface of the carbon/carbon composite w as not fully covered by an iridium coating up to 12 mum thick, whereas better deposition and surface coverage with the iridium coating were obtained on the polished surface and CVD pyro carbon-coated carbon/car bon composite surface. After heat treatment at 2000 K for 1 .2 ks, int erconnected islands of iridium were formed on three surfaces of the ca rbon/carbon composite. Iridium neither reacted with nor dissolved the carbon/carbon composite, it had some penetration but did not react to form an interfacial compound, and the boundary between the iridium and carbon/carbon composite was distinct.