High-pressure deformation of metallic glass nanoparticles

The atomistic structure of metallic glasses is closely related to properties such as strength and ductility. Here, Ni _1-xB _x metallic glass nanoparticles of two different sizes are compressed under quasi-hydrostatic high-pressure conditions in order to understand structural changes under stress. The structural changes in the nanoparticles were tracked using in situ high-pressure X-ray diffraction (XRD). The ambient pressure pair-distribution functions generated from XRD showed that the smaller sized nanoparticles had a more compact amorphous structure with lower coordination number. XRD showed that the amorphous structure was stable up to the maximum pressures achieved. The bulk modulus of the smaller and larger sized nanoparticles was found to be 183 GPa and 178 GPa, respectively. The size-dependent high-pressure behavior was related to compositional differences between the nanoparticles. These results show that Ni _1-xB _x metallic glass nanoparticles are highly stable under pressure.