Change in local structure and hardness in the amorphization process of Zr45Cu45Al10 alloy by heavy ion irradiation

Hypo-eutectic alloy of Zr45Cu45Al10 was irradiated with 16 MeV and 200 MeV Au ions at room temperature. Before and after irradiation, effects of the irradiation on the structure and hardness of the alloy were investigated by using X-ray diffraction (XRD), Extended X-ray absorption fine structure (EXAFS), micro-Vickers hardness and positron annihilation measurements. As a result of the irradiation, amorphization was confirmed for both en-ergies of the irradiations, but the behavior of hardness change strongly depends on the irradiation energy. That is, the hardness once decreases and increases with increasing the fluence in the case of 16 MeV irradiation, but in the case of 200 MeV irradiation, no decreasing trend was observed. The EXAFS measurement shows that the changing ratio of Cu-Cu and Cu-Zr bonds around each Cu atom is different between low energy and high energy Au ion irradiation.