Microstructural evolution and mechanical performance of AlNiCe amorphous thin films under proton irradiation

Amorphous alloys exhibit great resistance to irradiation due to the unique metastable configuration. This study systematically investigates the influence of proton irradiation on the microstructures and macroscopic mechanical properties of the AlNiCe amorphous thin film deposited by magnetron sputtering. It is found that with increasing proton irradiation energy, the local structure ordering degree increases progressively while preserving the amorphous phase, which directly contributes to a monotonical enhancement in both elastic modulus and hardness. Specifically, the improvement in modulus can be attributed to the irradiation induced densification effect. While the increase in hardness is owing to the suppression in both initiation and propagation of shear bands caused by free volume reduction. Coupled with the exceptional specific strength which is several times greater than conventional aluminum alloys and the excellent proton irradiation resistance, the AlNiCe amorphous thin film can be considered as a promising candidate material for engineering applications in low earth orbit.