Anisotropic and size-dependent mechanical responses of free-standing Ni-Nb metallic glass thin film

Scaling Law for Impact Resistance of Amorphous Alloys Connecting Atomistic Molecular Dynamics with Macroscale Experiments

“…Based on experimental results, the Ni 2 Ta MG film exhibits a brittle-to-ductile transition under ballistic impact similar to crystalline materials ,,− with decreasing thickness from 600 to 100 nm. The failure of the 600-nm-thick film shows a typical brittle fracture of the bulk MG material, while the 100-nm-thick film shows obvious plasticity as evidenced by the bending of the petals.…”

“…The ultrahigh impact resistance of the Ni 2 Ta MG nanofilm should be contributed by the size-dependent mechanical behavior at small scales. ,,− The strength and ductility of the nanoscale film increase significantly compared to its bulk state due to the considerable reduction of inner defects and the larger proportion of surface energy. Once the particle impacts the target, the center of the film is under compressive stress, while the surrounding is under tensile stress.…”

“…These results also validate that the scaling law remains applicable at the atomistic scale, bridging the gap between MD simulations and micro-ballistic impact experiments. In the regime of ballistic impact, the strength and ductility of material play significant roles. , Although the mechanical behavior of a film at a level of atomistic simulations varies markedly due to the size effects, ,,− the impact resistance of the nanofilm should still be determined by the strength and ductility. Therefore, we can scale successfully the impact resistance of amorphous alloy films between MD simulations and micro-ballistic impact experiments.…”