Lauren M. Garrison¹, Chad Parish¹, Maxim Gussev¹, John Echols¹, Johann Riesch²; ¹Oak Ridge National Laboratory, ²Max-Planck-Institut für Plasmaphysik

Tungsten fiber, tungsten matrix composites can improve the mechanical properties of tungsten in the divertors of fusion reactors. Such composites can improve the toughness as compared to standard sintered tungsten in the unirradiated condition, but their behavior after neutron irradiation is not known. Because the fibers are an integral part of the composite, individual fibers were neutron irradiated in the High Flux Isotope Reactor at temperatures between 400–1100°C to doses of ~0.2–0.7 dpa. Two types of fibers were irradiated: unalloyed tungsten and tungsten with 60 ppm potassium. All fibers had 150 µm diameter and approximately 40 mm length. For the irradiation, groups of fibers were held in small graphite bottles to prevent damage or loss during irradiation. The microstructure of the fibers was investigated with scanning and transmission electron microscopy and the mechanical properties were evaluated with tensile tests.