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

AbstractIntroducing 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.

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Room temperature plastic deformation behavior of ZrCuNiAl bulk metallic glasses

International Journal of Minerals Metallurgy and Materials ◽

10.1007/s12613-010-0313-9 ◽

2010 ◽

Vol 17 (3) ◽

pp. 327-330 ◽

Cited By ~ 3

Author(s):

Ping-jun Tao ◽

Yuan-zheng Yang ◽

Xiao-jun Bai ◽

Zhi-wei Xie ◽

Xian-chao Chen

Keyword(s):

Plastic Deformation ◽

Metallic Glasses ◽

Deformation Behavior ◽

Room Temperature ◽

Bulk Metallic Glasses ◽

Plastic Deformation Behavior

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On the question of fractal packing structure in metallic glasses

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1705723114 ◽

2017 ◽

Vol 114 (32) ◽

pp. 8458-8463 ◽

Cited By ~ 14

Author(s):

Jun Ding ◽

Mark Asta ◽

Robert O. Ritchie

Keyword(s):

Metallic Glasses ◽

Amorphous Materials ◽

Level Structure ◽

Atomic Scale ◽

Structure Property ◽

Packing Structure ◽

Structure Property Relationships ◽

Fractal Models ◽

Percolation Clusters ◽

Compositional Variations

This work addresses the long-standing debate over fractal models of packing structure in metallic glasses (MGs). Through detailed fractal and percolation analyses of MG structures, derived from simulations spanning a range of compositions and quenching rates, we conclude that there is no fractal atomic-level structure associated with the packing of all atoms or solute-centered clusters. The results are in contradiction with conclusions derived from previous studies based on analyses of shifts in radial distribution function and structure factor peaks associated with volume changes induced by pressure and compositional variations. The interpretation of such shifts is shown to be challenged by the heterogeneous nature of MG structure and deformation at the atomic scale. Moreover, our analysis in the present work illustrates clearly the percolation theory applied to MGs, for example, the percolation threshold and characteristics of percolation clusters formed by subsets of atoms, which can have important consequences for structure–property relationships in these amorphous materials.

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Expanding Monomers as Anti-Shrinkage Additives

Polymers ◽

10.3390/polym13050806 ◽

2021 ◽

Vol 13 (5) ◽

pp. 806

Author(s):

Philipp Marx ◽

Frank Wiesbrock

Keyword(s):

Ring Opening ◽

Covalent Bond ◽

Volumetric Shrinkage ◽

Structure Property ◽

Atomic Packing ◽

Materials Properties ◽

Volumetric Expansion ◽

Structure Property Relationships ◽

Ring Opening Reaction ◽

Measuring Techniques

Commonly, volumetric shrinkage occurs during polymerizations due to the shortening of the equilibrium Van der Waals distance of two molecules to the length of a (significantly shorter) covalent bond. This volumetric shrinkage can have severe influence on the materials’ properties. One strategy to overcome this volumetric shrinkage is the use of expanding monomers that show volumetric expansion during polymerization reactions. Such monomers exhibit cyclic or even oligocyclic structural motifs with a correspondingly dense atomic packing. During the ring-opening reaction of such monomers, linear structures with atomic packing of lower density are formed, which results in volumetric expansion or at least reduced volumetric shrinkage. This review provides a concise overview of expanding monomers with a focus on the elucidation of structure-property relationships. Preceded by a brief introduction of measuring techniques for the quantification of volumetric changes, the most prominent classes of expanding monomers will be presented and discussed, namely cycloalkanes and cycloalkenes, oxacycles, benzoxazines, as well as thiocyclic compounds. Spiroorthoesters, spiroorthocarbonates, cyclic carbonates, and benzoxazines are particularly highlighted.

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Atomic Scale Structure-Property Relationships of Defects and Interfaces in Ceramics

Microscopy and Microanalysis ◽

10.1017/s143192760002290x ◽

1998 ◽

Vol 4 (S2) ◽

pp. 556-557

Author(s):

S. Stemmer ◽

G. Duscher ◽

E. M. James ◽

M. Ceh ◽

N.D. Browning

Keyword(s):

Point Defects ◽

High Resolution Electron Microscopy ◽

Complete Characterization ◽

Atomic Scale ◽

Structure Property ◽

Defect Engineering ◽

Impurity Atoms ◽

Structure Property Relationships ◽

Resolution Electron ◽

Scale Composition

The evaluation of the two dimensional projected atom column positions around a defect or an interface in an electronic ceramic, as it has been performed in numerous examples by (quantitative) conventional high-resolution electron microscopy (HRTEM), is often not sufficient to relate the electronic properties of the material to the structure of the defect. Information about point defects (vacancies, impurity atoms), and chemistry or bonding changes associated with the defect or interface is also required. Such complete characterization is a necessity for atomic scale interfacial or defect engineering to be attained.One instructive example where more than an image is required to understand the structure property relationships, is that of grain boundaries in Fe-doped SrTi03. Here, the different formation energies of point defects cause a charged barrier at the boundary, and a compensating space charge region around it. The sign and magnitude of the barrier depend very sensitively on the atomic scale composition and chemistry of the boundary plane.

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Structural features of plastic deformation in bulk metallic glasses

Applied Physics Letters ◽

10.1063/1.4906305 ◽

2015 ◽

Vol 106 (3) ◽

pp. 031903 ◽

Cited By ~ 18

Author(s):

S. Scudino ◽

H. Shakur Shahabi ◽

M. Stoica ◽

I. Kaban ◽

B. Escher ◽

...

Keyword(s):

Plastic Deformation ◽

Metallic Glasses ◽

Bulk Metallic Glasses ◽

Structural Features

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Atomic-scale structural evolution in amorphous Nd9Fe85B6 subjected to severe plastic deformation at room temperature

Applied Physics Letters ◽

10.1063/1.3152013 ◽

2009 ◽

Vol 94 (23) ◽

pp. 231904 ◽

Cited By ~ 17

Author(s):

Wei Li ◽

Xiaohong Li ◽

Defeng Guo ◽

Kiminori Sato ◽

Dmitry V. Gunderov ◽

...

Keyword(s):

Plastic Deformation ◽

Severe Plastic Deformation ◽

Room Temperature ◽

Structural Evolution ◽

Atomic Scale

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Room Temperature Plasticity of Zr65Al7.5Ni10Cu17.5-xPdx Bulk Metallic Glasses

THERMEC 2006 - Materials Science Forum ◽

10.4028/0-87849-428-6.2054 ◽

2007 ◽

pp. 2054-2058

Author(s):

Kyosuke Yoshimi ◽

Hidemi Kato ◽

Junji Saida ◽

Akihisa Inoue

Keyword(s):

Metallic Glasses ◽

Room Temperature ◽

Bulk Metallic Glasses

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Atomic Scale Analysis of a YSZ Bicrystal Grain Boundary

Microscopy and Microanalysis ◽

10.1017/s1431927600028075 ◽

2001 ◽

Vol 7 (S2) ◽

pp. 400-401

Author(s):

Y. Lei ◽

Y. Ito ◽

N. D. Browning

Keyword(s):

Grain Boundary ◽

Grain Boundaries ◽

Bulk Material ◽

Atomic Scale ◽

Structure Property ◽

Contrast Imaging ◽

Structure Property Relationships ◽

Commercial Applications ◽

Z Contrast ◽

Electron Energy Loss

Yttria-stabilized zirconia (YSZ) has been the subject of many experimental and theoretical studies, due to the commercial applications of zirconia-based ceramics in solid state oxide fuel cells. Since the grain boundaries usually dominate the overall macroscopic performance of the bulk material, it is essential to develop a fundamental understanding of their structure-property relationships. Previous research has been performed on the atomic structure of grain boundaries in YSZ, but no precise atomic scale compositional and chemistry characterization has been carried out. Here we report a detailed analytical study of an [001] symmetric 24° bicrystal tilt grain boundary in YSZ prepared with ∼10 mol % Y2O3 by Shinkosha Co., Ltd by the combination of Z-contrast imaging and electron energy loss spectroscopy (EELS).The experimental analysis of the YSZ sample was carried out on a 200kV Schottky field emission JEOL 201 OF STEM/TEM4.

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