Orientation-dependent ion-irradiation responses in molybdenum and molybdenum-rhenium alloys.

• Helium ion-irradiation responses in Mo-Re alloys at room temperature were evaluated via micro-pillar compression. • Orientation-dependent irradiation-induced hardening is obvious in low Re Mo-Re alloys, while is weak on high Re alloys. • Irradiated pillars with [1 0 0] orientation all shows higher flow stresses than pillars with [1 1 0] orientation after yield. Helium ion-irradiation responses in molybdenum (Mo) and molybdenum-rhenium (Mo-Re) alloys at room temperature were evaluated via micro-pillar compression. Irradiation-induced hardening is closely dependent on orientation in Mo-Re alloys with low Re content, while is weak orientation-dependence on high Re alloys. Irradiated pillars with [1 0 0] orientation all shows higher flow stresses than pillars with [1 1 0] orientation after yield, which is distinguishing from pillars before irradiation that has been shown in our previous work. High density of dislocation loops and helium bubbles after irradiation at room temperature induces severe hardening in Mo. Voids / small loops induced by irradiation lead to less hardening in Mo-Re alloy than in Mo. No precipitation is observed in all samples, which may be attributed to low irradiated temperature and implantation energy. [ABSTRACT FROM AUTHOR]