Influence of the loading condition on the creep properties of a Cu-Cr-Zr alloy

Full text of publication follows: The first wall components used in ITER will be subjected to simultaneous creep and fatigue loading. The material chosen for the heat sink is a Cu-Cr-Zr alloy which needs to be bounded by hipping and brazing processes to stainless steel and beryllium parts. In this work, we will present the creep properties of the base material Cu-Cr-Zr, heat treated slightly differently as compared to the manufacturing route, so to ensure a grain size of the order of 200-400 μm. The material will be tested using two different techniques, at a temperature of 300 deg. C. A first set of specimens having a gauge diameter of 3 mm will be tested under constant stress and a second set of specimens with 6 mm diameter will be tested under constant load. The obtained results will be discussed as a function of the specimen size and loading conditions. In particular we will show how the loading condition influences the third stage of creep, in which the creep rate is increased. The evolution of the microstructure will be followed by transmission electron microscopy. (authors)