Ion-irradiation hardening of brazed joints of tungsten and oxide dispersion strengthened (ODS) ferritic steel

Abstract

Irradiation hardening and microstructural change of the brazed-joint of W and oxide dispersion strengthened ferritic steel (ODS-FS was investigated by nano-indentation hardness test and transmission electron microscopy after ion irradiation with 6.4MeV Fe3+ ions at 500°C up to 10 dpa. Dual-beam irradiation of Fe3+ ions and energy-degraded 1MeV He+ ion was also carried out. A considerable irradiation hardening occurred in the W base metal where dislocation loops and nano-scaled voids or He-bubbles were observed. Dual-beam irradiation enhanced the hardening. No significant hardening was observed in ODS-FS. The hardness of insert material was reduced after irradiation, which is due to the recovery of dislocations generated during joining process. © 2013 The Japan Institute of Metals.