JOINING OF SICF SIC COMPOSITES FOR THERMONUCLEAR FUSION-REACTORS/

Due to their favourable radiological behaviour, SiCf/SiC composites ar e promising structural materials for future use in fusion reactors. A problem to cope with is the joining of the ceramic composite material (CMC) to itself for more complex structures. Maintenance concepts for a reactor made of SiCf/SiC will demand a method of joining. The joinin g agents should comply with the low-activation approach of the base ma terial. With the acceptable elements Si and Mg, sandwich structures of composite/metal/composite were prepared in Ar atmosphere at temperatu res just above the melting points of the metals. Another promising rou te is the use of joining agents of bore-silicate glasses: their compos ition can be tailored to obtain softening temperatures of interest for fusion applications. The glassy joint can be easily ceramised to impr ove thermomechanical properties. The joining interfaces were investiga ted by SEM-EDS, XRD and mechanical tests.