Swift heavy ion irradiation effect on structural, morphological and mechanical properties of Zr₇₀Ni₃₀ metallic glass

Abstract

Metallic glass films are considered for coating applications in the nuclear field owing to their advantageous performances. However, the response to irradiation remains to be more thoroughly characterized. Zr70Ni30 metallic glass films were irradiated by 0.71MeV/u129Xe23+ ions in the fluence range from 5 × 1012 to 8 × 1013 ions cm−2. The structural, morphological, and mechanical properties were determined using grazing incidence X-ray diffraction (GI-XRD), atomic force microscopy (AFM), and nanoindentation for the as-deposited and irradiated samples. The Xe ion induced surface smoothening, thereby increasing the corrosion resistance. One-dimensional power spectral density of the AFM data of irradiated film demonstrated that the irradiation-induced evolution of the surface morphology could be attributed to a transition between viscous flow and the evaporation-condensation mechanism. The amorphous structure was unaffected after irradiation up to a fluence of 8 × 1013 ions cm−2. Nanoindentation revealed first a softening as the fluence increases up to 4 × 1013 ions cm−2, reflecting the creation of free volume defects. Then the hardness and Young’s modulus slightly increase when reaching 8 × 1013 ions cm−2. Moreover, at a critical dose of 0.008 dpa, the hardness is found to increase. Moreover, the calculation of the inelastic thermal spike model reveals the formation of the track with a radius of 7 nm.