EUROfusion characterisation programme of CuCrZr alloy for the EU DEMO divertor heat sink: mechanical and thermophysical properties

This paper summarises the progress in characterisation of the CuCrZr alloy selected for the cooling pipes of European DEMO divertor achieved by several laboratories within EUROfusion in the frame of a large experimental campaign. Since the high-temperature hot radial pressing (HRP) joining procedure will modify the material properties, the CuCrZr alloy has been tested after an HRP-simulating heat treatment to represent a DEMO-relevant material. The ongoing characterization campaign is filling gaps of mechanical and thermophysical properties in the current MPH version which contains limited information on CuCrZr after the relevant thermal treatment, and helps reduce unnecessary conservatism of divertor design. Neutron irradiation campaign is ongoing which will provide high-priority mechanical properties at high dose (1–9 dpa). The obtained material properties will be compiled in the DEMO Material Property Handbooks (MPH), which will be used by the DEMO divertor design team. Most of the scheduled high-priority mechanical and thermophysical tests have been completed on non-irradiated material, their results are presented and compared to the data from the DEMO CuCrZr MPH.