Effects of Helium Implantation on the Tensile Properties and Microstructure of Ni₇₃P₂₇ Metallic Glass Nanostructures

Abstract

We report fabrication and nanomechanical tension experiments on as-fabricated and helium-implanted ∼130 nm diameter Ni 73 P 27 metallic glass nanocylinders. The nanocylinders were fabricated by a templated electroplating process and implanted with He + at energies of 50, 100, 150, and 200 keV to create a uniform helium concentration of ∼3 atom % throughout the nanocylinders. Transmission electron microscopy imaging and through-focus analysis reveal that the specimens contained ∼2 nm helium bubbles distributed uniformly throughout the nanocylinder volume. In situ tensile experiments indicate that helium-implanted specimens exhibit enhanced ductility as evidenced by a 2-fold increase in plastic strain over as-fabricated specimens with no sacrifice in yield and ultimate tensile strengths. This improvement in mechanical properties suggests that metallic glasses may actually exhibit a favorable response to high levels of helium implantation.

Shear-banding Induced Indentation Size Effect in Metallic Glasses

“…Furthermore, through controlled surface ion-implantation, it was also demonstrated that nano-scale plasticity of MGs can be tuned by adjusting the dose of the implanted ions2223. In view of these recent findings20212223, one can conclude that the behavior of nano-scale shear-banding in MGs relies on how micro-samples are prepared. Hence, the issue of size effect on shear-banding in pristine MGs is not completely settled and more research efforts are still needed.…”

“…Compared to the micro- and nano-compression techniques, indentation does not entail a complicated process for preparing small-sized samples, such as the use of focused ion beam (FIB) to fabricate micro-/nano-pillars for testing, during which process surface defects might be introduced, thus altering the mechanical behaviors of the micro-samples so obtained202122. This is particularly so for MGs as noted in a few recent studies2122. According to Magagnosc et al 21,.…”

In situ heavy ion irradiation studies of nanopore shrinkage and enhanced radiation tolerance of nanoporous Au

“…The central premise is that certain types of defect sinks may promote the absorption and recombination of interstitials and vacancies and thus enhance the radiation tolerance of materials. Consequently, various types of defect sinks have been investigated, including grain boundary (GB), twin boundary (TB), phase boundary, etc101112131415161718. Nanocrystalline materials have abundant GBs and may have extraordinary radiation resistance because GBs act as defect sinks that can absorb irradiation induced defects, and in some cases may serve as sources to emit interstitials and annihilate vacancies1920212223.…”

Nitrogen Nanobubbles in a-SiOxNy Coatings: Evaluation of Its Physical Properties and Chemical Bonding State by Spatially Resolved Electron Energy-Loss Spectroscopy

“…[19][20][21][22][23][24][25] Generally these microstructures consist in few pores situated at a certain distance from the surface; while with our methodology, highly porous structures with uniform porosity from the substrate to the coatings surface are deposited, in a wide range of thicknesses (from 100 nm to few microns). From a fundamental point of view these new materials with embedded pores, filled with the sputtering gas, represent a new class of nanocomposite materials presenting on demand optical properties in comparison with the matrix film.…”