Atomistic design favored compositions and atomic-level structure of Mg–Ca–Ag ternary metallic glasses

Abstract The design of ductile heterogeneous metallic glasses (MGs) with enhanced deformability by purposely controlling the shear-band dynamics via modulation of the atomic-scale structures and local stress states remains a significant challenge. Here, we correlate the changes in the local atomic structure when cooling to cryogenic temperature with the observed improved shear stability. The enhanced atomic-level structural and elastic heterogeneities related to the nonaffine thermal contraction of the short-range order (SRO) and medium-range order (MRO) change the characteristics of the activation process of the shear transformation zones (STZs). The experimental observations corroborated by Eshelby inclusion analysis and molecular dynamics simulations disclose the correlation between the structural fluctuations and the change in the stress field around the STZ. The variations in the inclination axes of the STZs alter their percolation mechanism, affect the shear-band dynamics and kinetics, and consequently delay shear failure. These results expand the understanding of the correlation between the atomic-level structure and elementary plastic events in monolithic MGs and thereby pave the way for the design of new ductile metallic alloys.

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Atomic-level structure and structure–property relationship in metallic glasses

Progress in Materials Science ◽

10.1016/j.pmatsci.2010.12.002 ◽

2011 ◽

Vol 56 (4) ◽

pp. 379-473 ◽

Cited By ~ 918

Author(s):

Y.Q. Cheng ◽

E. Ma

Keyword(s):

Metallic Glasses ◽

Level Structure ◽

Atomic Level ◽

Structure Property ◽

Property Relationship ◽

Structure Property Relationship

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Correlation between atomic-level structure, packing efficiency and glass-forming ability in Cu–Zr metallic glasses

Journal of Non-Crystalline Solids ◽

10.1016/j.jnoncrysol.2014.07.035 ◽

2014 ◽

Vol 404 ◽

pp. 55-60 ◽

Cited By ~ 10

Author(s):

K.N. Lad

Keyword(s):

Metallic Glasses ◽

Level Structure ◽

Glass Forming Ability ◽

Atomic Level ◽

Structure Packing ◽

Glass Forming ◽

Packing Efficiency

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Hydrogen Storage in MgH2 Matrices: An Ab-Initio Study of Mg-MgH2 Interface

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.139.23 ◽

2008 ◽

Vol 139 ◽

pp. 23-28 ◽

Cited By ~ 2

Author(s):

Simone Giusepponi ◽

Massimo Celino ◽

Fabrizio Cleri ◽

Amelia Montone

Keyword(s):

Molecular Dynamics ◽

Total Energy ◽

Ab Initio ◽

Atomic Hydrogen ◽

Level Structure ◽

Atomic Level ◽

Work Of Adhesion ◽

Ab Initio Study ◽

Dynamics Method ◽

Good Agreement

We studied the atomic-level structure of a model Mg-MgH2 interface by means of the Car-Parrinello molecular dynamics method (CPMD). The interface was characterized in terms of total energy calculations, and an estimate of the work of adhesion was given, in good agreement with experimental results on similar systems. Furthermore, the interface was studied in a range of temperatures of interest for the desorption of hydrogen. We determined the diffusivity of atomic hydrogen as a function of the temperature, and give an estimate of the desorption temperature.

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