Precipitation of Solid Transmutation Elements in Irradiated Tungsten Alloys

Tungsten-based model alloys were fabricated to simulate compositional changes by neutron irradiation, performed in the JOYO fast test reactor. The irradiation damage range was 0.17-1.54 dpa and irradiation temperatures were 400, 500 and 750 degrees C. After irradiation, microstructural observations and electrical resistivity measurements were carried out. A number of precipitates were observed after 1.54 dpa irradiation. Rhenium and osmium were precipitated by irradiation, which suppressed the formation of dislocation loops and voids. Structures induced by irradiation were not observed so much after 0.17dpa irradiation. Electrical resistivity measurements showed that the effects of osmium on the electrical resistivity, related to impurity solution content, were larger than that of rhenium. Measurements of electrical resistivity of tertiary alloys showed that the precipitation behavior was similar to that in binary alloys. [doi: 10.2320/matertrans.MAW200821]