DESIGN OF LOW RESIDUAL-STRESS JOINTS BETWEEN 3D CC COMPOSITES AND GLIDCOP COPPER FOR DIVERTOR APPLICATIONS

An innovative approach to modeling the interfacial residual stress bet ween CC Composites and Glidcop copper is proposed. The model predictio ns were consistent with experimental observations in ceramic-metal joi nts where it was easier to visualize cracking, and later extended to c arbon-Glidcop copper joints. A variety of interface designs were inves tigated. The numerical predictions were consistent with experimental r esults in the Glidcop-ISO63 graphite system but less consistent in the C-C composite-Glidcop copper system. This inconsistency is presently attributed to the inhomogeneous nature of C-C composite in contrast to ISO63 graphite or Si3N4 ceramic. A joint design based on the numerica l results, comprising of grooves in the Glidcop copper and metallic in terlayers appeared to alleviate the residual stresses sufficiently eno ugh to allow bonding between C-C composite and Glidcop copper.