Damage induced by helium ion irradiation in Fe-based metallic glass

- Metallic glass Fe68Zr7B25 could maintain amorphous state after the irradiation.
- A series of crystallization behaviors occurred in metallic glass Fe80Si7.43B12.57.
- The surface of tungsten appeared blisters at the fluence of 1.0 × 1018 ions/cm2.
- Surfaces of Fe-based metallic glasses cracked at the fluence of 1.6 × 1018ions/cm2.

The changes in structure and surface morphology of metallic glasses Fe80Si7.43B12.57 and Fe68Zr7B25 before and after the irradiation of He ions with the energy of 300 keV were investigated, and were compared with that of the tungsten. The results show that after the He2+ irradiation, metallic glass Fe68Zr7B25 still maintained amorphous. While a small amount of metastable β-Mn type phase nanocrystals formed in metallic glass Fe80Si7.43B12.57 at the fluence of 4.0 × 1017ions/cm2 (19dpa). The nanocrystals transformed into α-Fe phase and tetragonal Fe2B phase as the fluence increased to 1.0 × 1018ions/cm2 (47dpa). Then the new orthogonal Fe3B phase and β-Mn type phase nanocrystals appeared when the fluence increased further, and the quantities of nanocrystals increased. Blisters and cracks appeared on the surface of tungsten under the irradiation fluence of 1.0 × 1018ions/cm2, however only when the fluence was up to 1.6 × 1018ions/cm2, could cracks and spalling appear on the surfaces of metallic glasses.

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