Microstructure of tantalum irradiated with heavy ions

For the purpose of investigating the general response of tantalum to irradiation, microstructures have been observed after irradiation with 3.0 or 2.4 MeV Cu²⁺ ions at 773 to 1546 K and to 20 dpa. Below 1073 K, the microstructures consisted mainly of high density of small dislocation loops and straight dislocations. The small dislocation loops observed were identified to be of vacancy-type. Voids were formed above 973 K, however, the swelling was negligibly small up to 20 dpa below ∼1100 K. High density of defects observed below 1073 K may cause significant change in mechanical properties. This may be a concern in applying tantalum to fusion high heat flux components.