Ultrastable Metallic Glass Nanoparticles with Size-Dependent Mechanical Properties

TL;DR

This study investigates the size-dependent structural stability and mechanical properties of Ni1-xBx metallic glass nanoparticles under high pressure, revealing their potential for use in composite materials.

Contribution

It provides the first detailed analysis of how nanoparticle size influences structural stability and mechanical response under high pressure in metallic glasses.

Findings

Smaller nanoparticles have more compact amorphous structures.

Both nanoparticle sizes remain amorphous and stable up to high pressures.

Smaller nanoparticles exhibit higher bulk modulus (208 GPa) than larger ones (178 GPa).

Abstract

The atomistic structure of metallic glasses is closely related to properties such as strength and ductility. Here, Ni1-xBx 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 208 GPa and 178 GPa, respectively. This size-dependent high-pressure behavior was related to compositional differences between the nanoparticles. These results show that Ni1-xBx metallic glass nanoparticles are highly stable under pressure, which could enable their use as inclusions in metal or ceramic matrix composites.