Development of fabrication technology and investigation of properties of steel-to-bronze joints suggested for ITER HHF components

When developing fabrication process for ITER High Heat Flux components, special attention shall be paid to the production of reliable joints between heat sink material made of CuCrZr bronze and support structure made of austenitic steel. Four different techniques have been proposed and tried: hot isostatic pressing (HIP), HIP-assisted brazing, furnace-assisted brazing, and casting. Investigation of joint structure and properties shows that HIP and casting give better results than other technologies. However, HIP is relatively expensive, and a big furnace is required to manufacture full-size components, which is not available in Russia now. Therefore, casting was selected as reference fabrication technique in Russia for the primary wall of ITER modules. The paper summarizes the outcome of the production effort for bronze-to-steel joints and the findings of the investigations into the properties of such joints.