High-temperature residual strain measurements, using neutron diffraction, in brazed Cu/CFC graphite divertor structures

This work presents a study of residual strain evolution in a three layer castelled mock-up for ITER obtained brazing carbon fibre composite (CFC) graphite with dispersion strengthened Cu (and with a GLIDCOP interlayer). Neutron diffraction measurements were carried out, on graphite at 30 degrees C, 300 degrees C and 600 degrees C and on dispersion strengthened (DS) Cu at 600 degrees C. For each material, the reference, unstrained value of the lattice parameter was obtained by measuring a powder of the same material at the same temperatures. While in DS Cu negligible strain values are found at high temperature, a more complicated evolution of the strains is observed in CFC graphite relating to sample geometry. (C) 1998 Elsevier Science B.V. All rights reserved.