Ponente
Descripción
The qualification of structural and functional materials for fusion reactors requires extensive mechanical testing under neutron irradiation. However, the limited irradiation volume available in current facilities and in future neutron sources such as IFMIF-DONES makes the use of conventional tensile specimens impractical. Small Specimen Test Technology (SSTT) has therefore emerged as a key approach for maximizing the amount of mechanical information obtained from irradiated material volumes. Nevertheless, the reduced dimensions of these specimens raise questions regarding transferability and the equivalence of the measured properties with respect to standard-sized specimens.
Within the framework of a EUROfusion Engineering Grant, an ongoing interlaboratory programme is being conducted to validate miniature tensile testing methodologies for two fusion-relevant materials: EUROFER97 and CuCrZr. The study includes several SSTT geometries, namely the European EUFLAT, the Japanese SSJ3, and the SCK-CEN cylindrical tensile specimen geometry, tested at different laboratories and temperatures. Particular attention is devoted to the development of robust testing procedures, specimen metrology, machine compliance correction and data processing methodologies, together with the assessment of the influence of microstructure, grain size, specimen dimensions and surface roughness on the reproducibility and transferability of key tensile properties such as yield strength, ultimate tensile strength and elongation.
The ultimate objective of this work is to contribute to the qualification of SSTT methodologies that can be reliably applied to future irradiated materials campaigns. The results obtained will support the future exploitation of IFMIF-DONES by providing validated mechanical testing procedures capable of extracting meaningful tensile properties from the limited material volumes available after irradiation. In this sense, the work represents a necessary step towards the generation of qualification data for fusion structural and high-heat-flux materials under representative irradiation conditions.