Tensile properties and constitutive laws of ITER grade CuCrZr alloy

In this work, systematic tensile tests and true stress - true strain data extraction is performed for ITER-grade CuCrZr alloy. The investigated alloy has been exposed to a dedicated thermal treatment to mimic the hot radial pressing (HRP) process, which will be applied to fabricate plasma-facing units for divertor of DEMO and possible other fusion facilities. CuCrZr alloy would serve as cooling pipe and therefore will be categorized as structural material with a safety important class. HRP induces considerable modifications in the microstructure due to elevated temperature exposure, so that mechanical properties deviate from the original material used to fabricate the pipes. As of today, there is no information on the tensile properties of CuCrZr alloy in its technological condition corresponding to the hot radial pressed condition cycle. We provide dataset of tensile properties from room temperature up to 350°C, corresponding to an upper design operational temperature for ITER and DEMO, as well as establish constitutive material laws, including work hardening curves and the GTN damage model parameters, which enable accurate reproduction of elastic-plastic deformation and fracture using the finite element method (FEM). To achieve this, two-dimensional digital image correlation was applied to determine the reduction of cross-sectional area during testing, and fractographic analysis was carried out to characterize fracture mechanisms at different temperatures. To substantiate the selection of parameters for the GTN model, we performed microstructural analysis of the fracture surface using scanning electron microscopy. The study revealed a clear transition from fine dimples at room temperature to larger voids at elevated temperatures, confirming the ductile nature of the fracture. Numerical FEM simulations reproduced the experimental stress–strain curves with high accuracy including the fracture initiation point, demonstrating the temperature-dependent evolution of void nucleation with true plastic strain.