The irradiation effect on mechanical properties of joined structures as divertor target plate for fusion reactors

In order to evaluate neutron irradiation effect on divertor target plate co mponent, brazed specimens of C/C composite armor tile on alumina dispersed copper and HIPed specimen of beryllium on alumina dispersed copper were irr adiated up to a fluence of 2.8 x 10(23) n/m(2)(> 0. 18 MeV) at 746-788 K, a nd their strength tests were performed. From these tests, the following results were obtained. (1) MFC-1/alumina dispersed copper brazed-specimen Tensile and 4 point bend ing strength of irradiated brazed-specimen was 30-55% of that of unirradiat ed one. Tensile and 4 point bending strength of unirradiated and irradiated brazed- specimen increased as the test temperature was increased, however these str ength decreased above 600 K. Remarkable degradation of tensile strength was observed for the irradiated brazed-specimen above 600 K. Fracture position of irradiated specimen shifts from MFC-1 side brazed zone to alumina dispe rsed copper as the testing temperature increases. (2) Beryllium/alumina dispersed copper HIPed specimen Under tensile and bending loading, irradiated HIPed-specimen exhibits simil ar deformation behavior as copper alloy. but fracture strength of the speci men was dominated by fracture strain limitation of beryllium material. Tens ile and 4 point bending strength of irradiated HIPed-specimen showed 10-20% lower values than that of unirradiated one. The room-temperature strength of irradiated joint was about 3 times higher than that of the irradiated MF C-1/alumina dispersed copper brazed-specimen. Tensile and 4 point bending f racture strains of irradiated joint showed 0-30% lower values than that of unirradiated one. Fracture of irradiated HIPed-specimens was observed at jo ined area.