Qualification of Grain Oriented, Additively Manufactured Tungsten in DIII-D

Additively manufactured tungsten (AM-W) is a promising candidate for plasma-facing components in fusion reactors; however, its performance under reactor-relevant conditions require additional studies. This study exposed AM-W samples using DiMES in DIII-D. Initial results following the exposure of the AM-W samples to H-mode conditions in DIII-D did not show any visual damage on the surface. The AM process enables the control of grain orientation through tuning of manufacturing parameters such as electron beam speed and energy density. The exposed samples vary in grain orientations (dominantly (001) or (111)), geometries (flat and angled) as well as sample orientation parallel (II) and perpendicular (⟂) to AM build direction. In addition to the AM-W samples, 'ITER-grade' rolled W were included for comparison. These samples were pre-characterized using SEM and EBSD to obtain images of the surface morphology and grain orientation pre-exposure. The first DiMES head experienced a heat flux of 2.3 MW/m2 while the second DiMES head experienced a heat flux of 2.8 MW/m2. Although both heads did not experience any visual damage on the surface, further characterization will investigate microstructural changes.