Microstructural response of tungsten-based alloys to neutron irradiation

The microstructural evolution of several W-based alloys under neutron irradiation was investigated to assess the influence of irradiation temperature, alloy composition, and microstructure on radiation damage evolution. W-Y₂O₃, W-TiC, K-doped W, and K-doped W- 3 wt.% Re alloys were irradiated to ∼1 dpa at 600 °C and 1100 °C and characterized using transmission electron microscopy (TEM) combined with STEM-EDX analysis. The results show that irradiation at 1100 °C leads to the formation of larger defects with a lower number density compared to irradiation at 600 °C. Despite these general trends, pronounced differences in defect evolution are observed among the investigated alloys. The W-Y₂O₃ alloy exhibits a defect population similar to that of unalloyed W, whereas the W-TiC alloy shows a pronounced suppression of void formation accompanied by an increased density of dislocation loops. This anomalous behavior is attributed to the partial dissolution of Ti in the W matrix and its interaction with radiation-induced point defects. K-doped W displays a defect structure comparable to that of pure W, while K-bubbles do not act as preferential segregation sites for transmutation-induced elements.