Nickel nanoparticles set a new record of strength

Abstract

Material objects with micrometer or nanometer dimensions can exhibit much higher strength than macroscopic objects, but this strength rarely approaches the maximum theoretical strength of the material. Here, we demonstrate that faceted single-crystalline nickel (Ni) nanoparticles exhibit an ultrahigh compressive strength (up to 34 GPa) unprecedented for metallic materials. This strength matches the available estimates of Ni theoretical strength. Three factors are responsible for this record-high strength: the large Ni shear modulus, the smooth edges and corners of the nanoparticles, and the thin oxide layer on the particle surface. This finding is supported by molecular dynamics simulations that closely mimic the experimental conditions, which show that the mechanical failure of the strongest particles is triggered by homogeneous nucleation of dislocation loops inside the particle. The nucleation of a stable loop is preceded by multiple nucleation attempts accompanied by unusually large local atomic displacements caused by thermal fluctuations.

Influence of an amorphous surface layer on the mechanical properties of metallic nanoparticles under compression

“…This study emphasizes a particular increase of the yield strength for rounded systems due to a decrease of the contact surface area, and a transition towards a homogeneous dislocation nucleation process for a given range of sample sizes and roundness. Both results were confirmed by Sharma and collaborators [15], in the case of faceted Ni NPs using SEM compression tests and MD. In the latter case, the authors also underline the crucial role of the thin surface oxide layer (observed in the experiments) on the elevated strengths of the NPs.…”

Nickel: Human Health and Environmental Toxicology

“…It is also noted that kitchen kettles may release nickel into drinking water when it is boiled in kettles with nickel-plated elements. Finally, nickel nanoparticles (NiNPs) are among the most widely used nanomaterials, which are employed in many fields, such as catalysts, magnetic materials, biological medicines, conductive pastes and additive to lubricant [31][32][33].…”

Nickel nanoparticles inside carbon nanostructures: atomistic simulation

“…Numerous molecular dynamics simulations of Ni nanoparticles are conducted using embedded atom method parametrization for interatomic potential that reproduces reasonably well the properties of Ni clusters. However, it should be noted, that such studies were devoted to single metal nanoparticles interacting with each other or different metal NP to study the interaction kinetics, melting process, to name a few (Henz et al 2009;Sharma et al 2018;Yousefia and Khoie 2015;Joshi et al 2010). Even though application of Morse potential is the simplification of the real systems, it can provide results of physical relevance.…”