The microstructure of laser welded Y doped V–4Cr–4Ti alloys after ion irradiation

Laser welded V–4Cr–4Ti–0.15Y alloy, fabricated by National Institute for Fusion Science (NIFS), was used in this study. Copper ion irradiation was carried out with the tandem accelerator at Kyushu University. The TEM samples were sliced from the welded materials and irradiated at 873 K up to the dose of 12 dpa. The microstructure before the irradiation showed that relatively large precipitates, which were commonly observed in the alloy, disappeared in the center of the weld metal. After the ion irradiation, fine titanium oxides with {1 0 0} habit planes were detected. However, in all irradiation doses, the growth of titanium oxides was suppressed by Y addition.