Effect of neutron irradiation on mechanical properties of Cu/SS joints after single and multiple HIP cycles

The present design of the ITER plasma facing components consists of a coppe r alloy heat sink layer between plasma facing materials and stainless steel structure. The main option for manufacturing these components is hot isost atic pressing (HIP) method and several HIP thermal cycles are foreseen for manufacturing of the complete blanket module. Mechanical characterisation o f HIP joints between dissimilar metals is a complicated issue, where inform ation on mechanical properties of base alloys, metallurgy of the HIP joints and mechanical testing methods will be required. The tensile and three poi nt bend tests produced different fracture modes, depending on test temperat ure, applied HIP thermal cycles and neutron irradiation. The fracture mode was either ductile fracture of copper alloy or joint interface fracture. Th e mechanical properties of the HIP joint specimens were dominated by streng th mismatch of the base alloys which was affected by HIP thermal cycles and neutron irradiation. (C) 2000 Elsevier Science B.V. All rights reserved.