Nanoglass–Nanocrystal Composite—a Novel Material Class for Enhanced Strength–Plasticity Synergy

Abstract

The properties of a material can be engineered by manipulating its atomic and chemical architecture. Nanoglasses which have been recently invented and comprise nanosized glassy particles separated by amorphous interfaces, have shown promising properties. A potential way to exploit the structural benefits of nanoglasses and of nanocrystalline materials is to optimize the composition to obtain crystals forming within the glassy particles. Here, a metastable Fe‐10 at% Sc nanoglass is synthesized. A complex hierarchical microstructure is evidenced experimentally at the atomic scale. This bulk material comprises grains of a Fe90Sc10 amorphous matrix separated by an amorphous interfacial network enriched and likely stabilized by hydrogen, and property‐enhancing pure‐Fe nanocrystals self‐assembled within the matrix. This composite structure leads a yield strength above 2.5 GPa with an exceptional quasi‐homogeneous plastic flow of more than 60% in compression. This work opens new pathways to design materials with even superior properties.

Controlling shear band instability by nanoscale heterogeneities in metallic nanoglasses

“…An interesting observation here is that the effect of Article chemical segregation is found to be negligible in both Pd-Si and Ni-P nanoglasses. Improved plasticity was also reported in Fe 90 Sc 10 nanocomposites where Fe nanocrystals were found to be distributed in the amorphous matrix [15]. Besides plasticity, significant variation of the yield strength was also reported in literature, with Cu-Zr and Sc 75 Fe 25 nanoglasses showing higher yield strength during nanoindentation, while Pd-Si and Ni-P showed lower yield strength during micro-pillar tests compared to their conventional amorphous counterparts [10,11,14,16].…”

“…α-Fe is a by-product of the IGC synthesis because of the inherent difficulty in controlling the evaporation of the Fe-Sc alloy. From the characterization performed on the Fe-Sc nanocomposites, it was concluded that they are primarily composed of interfaces, cores and α-Fe crystallites [15]. Previous reports claimed that the segregation between core and interfaces is not very significant, only in the order of few atomic percent [23].…”

“…We would also try to shed some light on the reasons for the improvement in mechanical behavior of nanoglasses. For this purpose, we have taken into consideration two alloy systems with crystalline and amorphous heterogeneities i.e., Cu-Zr, where amorphous heterogeneities were present [10] and Fe-Sc, where crystalline dispersions were revealed by advanced characterization tools like atom probe tomography (APT) and field ion microscopy (FIM) [15]. To this end, micro-compression tests on Cu-Zr and Fe-Sc nanoglasses/composites are performed and compared with conventional metallic glass of the same composition.…”

Metal matrix nanocomposites in tribology: Manufacturing, performance, and mechanisms

“…An amorphous-crystalline oxidic nanocomposite surface layer (with a combination of high strength and high ductility) upon dry sliding has been achieved. The essential idea for this achievement is to use the high strength of metallic glass, while improving its homogeneous plastic deformability on surface by reducing deformation localization in shear bands (e.g., by introducing multiple shear bands) [1,177]. The coexistence of nanocrystal phase and amorphous phase helps achieve this goal, as shown in Fig.…”

Effect of Structural Relaxation on the Indentation Size Effect and Deformation Behavior of Cu–Zr–Based Nanoglasses

“…With this motivation, Gleiter and coworkers (Jing et al, 1989;Gleiter, 2008;Gleiter, 2009;Gleiter, 2013;Gleiter, 2016) proposed the concept of nanoglasses (NGs) consisting of glassy grains (GGs) separated by glassy interfaces (GIs) of higher free volume, and later, several researchers have successfully fabricated NGs using different manufacturing routes (Gleiter et al, 2014;Nandam et al, 2017;Ivanisenko et al, 2018;Nandam et al, 2020). Extensive studies have been conducted on NGs to investigate their mechanical and functional properties using both experiments and simulations (Chen et al, 2011;Ritter et al, 2011;Sopu et al, 2011;Wang et al, 2011;Ritter and Albe, 2012;Adibi et al, 2013;Albe et al, 2013;Witte et al, 2013;Wang et al, 2014;Adjoud and Albe, 2016;Sniadecki et al, 2016;Nandam et al, 2017;Hirmukhe et al, 2019;Arnold et al, 2020;Singh et al, 2020a;Singh et al, 2020b;Hirmukhe et al, 2020;Katnagallu et al, 2020;Nandam et al, 2020). A series of MD simulation studies have been performed on NGs with different GG sizes and observed that the plasticity increases with the decreasing size of the GGs.…”