SOLID-STATE DIFFUSION BONDING OF ALUMINA DISPERSION-STRENGTHENED COPPER TO 316-STAINLESS-STEEL

Joints of alumina dispersion-strengthened copper (DS Cu) to 316 stainless steel are expected to be used for the cooling pipes of the divertor in the ITER project. In this study, solid-state diffusion bonding has been carried out to investigate the influence of the bonding conditions on the strength of the joints. The bonding temperatures had a greater effect on the strength of the joints than the pressures or hold time. The tensile strength of the joint, which was obtained at a bonding temperature of 1173 K and pressure of 4.8 MPa, was almost the same as that of DS Cu. The absorbed energy of the joints was lower than that of DS Cu, though it increased with increasing temperature. The low cycle fatigue strength of the joint was nearly equal to that of the DS Cu. Intermetallic compounds were observed and had an influence on the impact strength.