Browse
Submit Data
Databases
API
Help

Dataset Information

31 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Composition effect on intrinsic plasticity or brittleness in metallic glasses.

ABSTRACT: The high plasticity of metallic glasses is highly desirable for a wide range of novel engineering applications. However, the physical origin of the ductile/brittle behaviour of metallic glasses with various compositions and thermal histories has not been fully clarified. Here we have found that metallic glasses with compositions at or near intermetallic compounds, in contrast to the ones at or near eutectics, are extremely ductile and also insensitive to annealing-induced embrittlement. We have also proposed a close correlation between the element distribution features and the plasticity of metallic glasses by tracing the evolutions of the element distribution rearrangement and the corresponding potential energy change within the sliding shear band. These novel results provide useful and universal guidelines to search for new ductile metallic glasses at or near the intermetallic compound compositions in a number of glass-forming alloy systems.

SUBMITTER: Zhao YY

PROVIDER: S-EPMC4104394 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Composition effect on intrinsic plasticity or brittleness in metallic glasses.

Zhao Yuan-Yun YY Inoue Akihisa A Chang Chuntao C Liu Jian J Shen Baolong B Wang Xinmin X Li Run-Wei RW

Scientific reports 20140721

The high plasticity of metallic glasses is highly desirable for a wide range of novel engineering applications. However, the physical origin of the ductile/brittle behaviour of metallic glasses with various compositions and thermal histories has not been fully clarified. Here we have found that metallic glasses with compositions at or near intermetallic compounds, in contrast to the ones at or near eutectics, are extremely ductile and also insensitive to annealing-induced embrittlement. We have ...[more]

PMID: 25043428

Similar Datasets

Extra plasticity governed by shear band deflection in gradient metallic glasses.

Project description:Inspired by gradient materials in nature, advanced engineering components with controlled structural gradients have attracted substantial research interests due to their exceptional combinations of properties. However, it remains challenging to generate structural gradients that penetrate through bulk materials, which is essential for achieving enhanced mechanical properties in metallic materials. Here, we report practical strategies to design controllable structural gradients in bulk metallic glasses (BMGs). By adjusting processing conditions, including holding time and/or controlling temperatures, of cryogenic thermal cycling and fast cooling, two different types of gradient metallic glasses (GMGs) with spatially gradient-distributed free volume contents can be synthesized. Both mechanical testing and atomistic simulations demonstrate that the spatial gradient can endow GMGs with extra plasticity. Such an enhanced mechanical property is governed by the gradient-induced deflection of shear deformation that fundamentally suppresses the unlimited shear localization on a straight plane that would be expected in BMGs without such a gradient.

| S-EPMC9018681 | biostudies-literature

Critical fictive temperature for plasticity in metallic glasses.

Project description:A long-sought goal in metallic glasses is to impart ductility without conceding their strength and elastic limit. The rational design of tough metallic glasses, however, remains challenging because of the inability of existing theories to capture the correlation between plasticity, composition and processing for a wide range of glass-forming alloys. Here we propose a phenomenological criterion based on a critical fictive temperature, T(fc), which can rationalize the effect of composition, cooling rate and annealing on room-temperature plasticity of metallic glasses. Such criterion helps in understanding the widespread mechanical behaviour of metallic glasses and reveals alloy-specific preparation conditions to circumvent brittleness.

| S-EPMC3586724 | biostudies-other

Origin of large plasticity and multiscale effects in iron-based metallic glasses.

Project description:The large plasticity observed in newly developed monolithic bulk metallic glasses under quasi-static compression raises a question about the contribution of atomic scale effects. Here, nanocrystals on the order of 1-1.5?nm in size are observed within an Fe-based bulk metallic glass using aberration-corrected high-resolution transmission electron microscopy (HRTEM). The accumulation of nanocrystals is linked to the presence of hard and soft zones, which is connected to the micro-scale hardness and elastic modulus confirmed by nanoindentation. Furthermore, we performed systematic simulations of HRTEM images at varying sample thicknesses, and established a theoretical model for the estimation of the shear transformation zone size. The findings suggest that the main mechanism behind the formation of softer regions are the homogenously dispersed nanocrystals, which are responsible for the start and stop mechanism of shear transformation zones and hence, play a key role in the enhancement of mechanical properties.

| S-EPMC5889395 | biostudies-literature

Substantially enhanced plasticity of bulk metallic glasses by densifying local atomic packing.

Project description:Introducing regions of looser atomic packing in bulk metallic glasses (BMGs) was reported to facilitate plastic deformation, rendering BMGs more ductile at room temperature. Here, we present a different alloy design approach, namely, doping the nonmetallic elements to form densely packed motifs. The enhanced structural fluctuations in Ti-, Zr- and Cu-based BMG systems leads to improved strength and renders these solutes' atomic neighborhoods more prone to plastic deformation at an increased critical stress. As a result, we simultaneously increased the compressive plasticity (from ∼8% to unfractured), strength (from ∼1725 to 1925 MPa) and toughness (from 87 ± 10 to 165 ± 15 MPa√m), as exemplarily demonstrated for the Zr20Cu20Hf20Ti20Ni20 BMG. Our study advances the understanding of the atomic-scale origin of structure-property relationships in amorphous solids and provides a new strategy for ductilizing BMG without sacrificing strength.

| S-EPMC8590062 | biostudies-literature

Shear-banding Induced Indentation Size Effect in Metallic Glasses.

Project description:Shear-banding is commonly regarded as the "plasticity carrier" of metallic glasses (MGs), which usually causes severe strain localization and catastrophic failure if unhindered. However, through the use of the high-throughput dynamic nanoindentation technique, here we reveal that nano-scale shear-banding in different MGs evolves from a "distributed" fashion to a "localized" mode when the resultant plastic flow extends over a critical length scale. Consequently, a pronounced indentation size effect arises from the distributed shear-banding but vanishes when shear-banding becomes localized. Based on the critical length scales obtained for a variety of MGs, we unveil an intrinsic interplay between elasticity and fragility that governs the nanoscale plasticity transition in MGs. Our current findings provide a quantitative insight into the indentation size effect and transition mechanisms of nano-scale plasticity in MGs.

| S-EPMC4914989 | biostudies-literature

Towards the Better: Intrinsic Property Amelioration in Bulk Metallic Glasses.

Project description:Tailoring the intrinsic length-scale effects in bulk metallic glasses (BMGs) via post-heat treatment necessitates a systematic analyzing strategy. Although various achievements were made in the past years to structurally enhance the properties of different BMG alloys, the influence of short-term sub-glass transition annealing on the relaxation kinetics is still not fully covered. Here, we aim for unraveling the connection between the physical, (thermo)mechanical and structural changes as a function of selected pre-annealing temperatures and time scales with an in-house developed Cu46Zr44Al8Hf2 based BMG alloy. The controlled formation of nanocrystals below 50 nm with homogenous distribution inside the matrix phase via thermal treatment increase the material's resistance to strain softening by almost an order of magnitude. The present work determines the design aspects of metallic glasses with enhanced mechanical properties via nanostructural modifications, while postulating a counter-argument to the intrinsic property degradation accounted for long-term annealing.

| S-EPMC4897615 | biostudies-other

A Series of Zr-Based Bulk Metallic Glasses with Room Temperature Plasticity.

Project description:A group of plastic Zr-Al-Ni-Cu bulk metallic glasses (BMGs) with low Zr content was developed and their thermal and mechanical properties were investigated. The results show that these Zr-based BMGs have a single crystallization event for all heating rates in the studied temperature region. The glass transition temperature Tg decreases with increasing Zr content for all heating rates. There are two melting procedures for the BMGs whose Zr content is less than 52 at %, while three melting procedures for the other Zr-based BMGs. The second melting procedure is split into two melting procedures for Zr52.5Al12.2Ni12.6Cu22.7 and Zr53Al11.6Ni11.7Cu23.7 BMGs, while the first melting procedure is split into two melting procedures for the other BMGs. The activation energy decreases with increasing sensitivity index β for the studied Zr-based BMGs. The plastic strain εp is in the region of 0.2%-19.1% for these Zr-based BMGs. Both yield strength σy and fracture strength σf are smallest for Zr55Al8.9Ni7.3Cu28.8 BMG whose εp is largest among all studied Zr-based BMGs and reaches up to 19.1%. In addition, the mechanism for the large difference of the plasticity among the studied Zr-based BMGs is also discussed.

| S-EPMC5456836 | biostudies-other

Tunable Tensile Ductility in Metallic Glasses

Project description:Widespread adoption of metallic glasses (MGs) in applications motivated by high strength and elasticity combined with plastic-like processing has been stymied by their lack of tensile ductility. One emerging strategy to couple the attractive properties of MGs with resistance to failure by shear localization is to employ sub-micron sample or feature length scales, although conflicting results shroud an atomistic understanding of the responsible mechanisms in uncertainty. Here, we report in situ deformation experiments of directly moulded Pt57.5Cu14.7Ni5.3P22.5 MG nanowires, which show tunable tensile ductility. Initially brittle as-moulded nanowires can be coerced to a distinct glassy state upon irradiation with Ga+ ions, leading to tensile ductility and quasi-homogeneous plastic flow. This behaviour is reversible and the glass returns to a brittle state upon subsequent annealing. Our results suggest a novel mechanism for homogenous plastic flow in nano-scaled MGs and strategies for circumventing the poor damage tolerance that has long plagued MGs.

| S-EPMC3549577 | biostudies-literature

Effect of surface and internal defects on the mechanical properties of metallic glasses.

Project description:Despite the significance of surface effects on the deformation behaviours of small-scale metallic glasses, systematic investigations on surface states are lacking. In this work, by employing atomistic simulations, we characterise the distributions of local inhomogeneity near surfaces created by casting and cutting, along with internal distributions in pristine and irradiated bulk specimens, and investigate the effects of inhomogeneity on the mechanical properties. The cast surface shows enhanced yield strength and degrees of shear localisation, while the cut surface shows the opposite effects, although the fraction of vibrational soft spots, known to indicate low-energy barriers for local rearrangement, is high near both surfaces. Correspondingly, plastic deformation is initiated near the cut surface, but far from the cast surface. We reveal that improved local orientational symmetry promotes strengthening in cast surfaces and originates from the effectively lower quenching rate due to faster diffusion near the surface. However, a significant correlation among vibrational soft spots, local symmetries, and the degree of shear localisation is found for the pristine and irradiated bulk materials. Our findings reveal the sensitivity of the surface state to the surface preparation methods, and indicate that particular care must be taken when studying metallic glasses containing free surfaces.

| S-EPMC5647394 | biostudies-literature

Effect of the Free Volume on the Electronic Structure of Cu70Zr30 Metallic Glasses.

Project description:While it is accepted that the plastic behavior of metallic glasses is affected by their free volume content, the effect on chemical bonding has not been investigated systematically. According to electronic structure analysis, the overall bond strength is not significantly affected by the free volume content. However, with an increasing free volume content, the average coordination number decreases. Furthermore, the volume fraction of regions containing atoms with a lower coordination number increases. As the local bonding character changes from bonding to anti-bonding with a decreasing coordination number, bonding is weakened in the volume fraction of a lower coordination number. During deformation, the number of strong, short-distance bonds decreases more for free volume-containing samples than for samples without free volume, resulting in additional bond weakening. Therefore, we show that the introduction of free volume causes the formation of volume fractions of a lower coordination number, resulting in weaker bonding, and propose that this is the electronic structure origin of the enhanced plastic behavior reported for glasses containing free volume.

| S-EPMC7672583 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data