Distribution of electrical energy through subsea power cables has an increasingly important role in the renewable power generation. The majority of the subsea cables uses copper (Cu) as a conductor material. Cables suspended from sea level to sea floor are subjected to both static and cyclic loads that can introduce microstructural damage due to fatigue, creep and their interaction. In addition, since the manufacturing process of the stranded conductor results in Cu-materials with superficial irregularities and metallurgical anisotropy, the material performances need to be carefully addressed in order to reliably assess the wires life. In order to provide a deeper insight into the occurring damage mechanisms, monotonic and cyclic tests of micro-sized Cu tensile specimens were carried out using in-situ micromechanical testing, inside a scanning electron microscopy (SEM) equipped with an electron backscatter diffraction. Tensile and cyclic loading behavior are discussed in correlation with the damage mechanisms observed directly and post-mortem. The twin boundary fraction in the microstructure is found to be linked to the deformation status, and thus can potentially be used as an indicator for predicting the remaining life of the material under service conditions.

通过海底电缆分配电能在可再生能源发电中发挥着越来越重要的作用。大多数海底电缆使用铜 (Cu) 作为导体材料。从海平面悬垂到海床的电缆会承受静态和循环载荷，这些载荷会因疲劳、蠕变及其相互作用而导致微观结构损坏。此外，由于绞合导体的制造过程导致铜材料具有表面不规则性和冶金各向异性，因此需要仔细考虑材料性能，以便可靠地评估电线寿命。为了更深入地了解发生的损伤机制，使用原位进行了微型铜拉伸试样的单调和循环测试在配备电子背散射衍射的扫描电子显微镜 (SEM) 内进行微机械测试。拉伸和循环加载行为与直接观察和事后观察到的损伤机制相关联进行了讨论。发现微观结构中的孪晶边界分数与变形状态有关，因此可以潜在地用作预测材料在使用条件下的剩余寿命的指标。