Effect of yttrium doping in tungsten on sinterability and properties as a plasma-facing material

Abstract

Y2O3 is extensively used to fabricate oxide-dispersion-strengthened tungsten to refine grain size, improve thermal stability, and increase high-temperature strength. However, excessive Y2O3 addition weakens the grain-boundary strength, which increases the ductile-to-brittle transition temperature. Therefore, in this study, a small amount of Y-rich precipitates was dispersed in a tungsten matrix through internal oxidation during spark plasma sintering. The phase, morphology, and size of the Y-rich precipitates in the sintered tungsten were characterized by transmission electron microscopy (TEM) and small-angle neutron scattering (SANS) analyses. Additionally, the effects of Y doping on sinterability, thermal stability, deuterium irradiation resistance, and mechanical properties were analyzed using Y-free pure tungsten specimens for comparison.