Role of atomic-scale chemical heterogeneities in improving the plasticity of Cu-Zr-Ag bulk amorphous alloys

Hong Kyu Kim, Jae Pyoung Ahn, Byeong Joo Lee, Kyoung Won Park, Jae-chul Lee

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

The addition of minor elements to binary amorphous alloys often results in simultaneous improvement in plasticity and strength. This is particularly the case for alloy systems that promote atomic-scale compositional separation during quenching. Considering that plasticity and strength are two contrasting properties originating from different atomic-scale structures characterized by short-range orders (SROs), this experimental observation at first seems contradictory when viewed from an SRO perspective. We performed comparative studies on (Cu0.5Zr0.5)100-xAgx amorphous alloys using experiments and molecular dynamics (MD) simulations to elucidate how these two mutually exclusive properties can be realized at the same time. MD simulations showed that while the addition of Ag promotes the formation of stable icosahedral orders responsible for improved strength, it also encourages the formation of weak/unstable Ag-bearing polyhedra that mitigate strain localization. In this study, the mechanistic origin of the enhanced plasticity is assessed by introducing a new descriptor that can quantitatively evaluate the characteristics of Ag-bearing polyhedra in terms of their size, softness, population, and spatial uniformity.

Original languageEnglish
Pages (from-to)209-217
Number of pages9
JournalActa Materialia
Volume157
DOIs
Publication statusPublished - 2018 Sep 15

Fingerprint

Amorphous alloys
Bearings (structural)
Plasticity
Molecular dynamics
Binary alloys
Computer simulation
Quenching
Experiments

Keywords

  • Amorphous alloy
  • Compositional separation
  • Mechanical properties
  • Molecular dynamics
  • Short-range orders

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys

Cite this

Role of atomic-scale chemical heterogeneities in improving the plasticity of Cu-Zr-Ag bulk amorphous alloys. / Kim, Hong Kyu; Ahn, Jae Pyoung; Lee, Byeong Joo; Park, Kyoung Won; Lee, Jae-chul.

In: Acta Materialia, Vol. 157, 15.09.2018, p. 209-217.

Research output: Contribution to journalArticle

Kim, Hong Kyu ; Ahn, Jae Pyoung ; Lee, Byeong Joo ; Park, Kyoung Won ; Lee, Jae-chul. / Role of atomic-scale chemical heterogeneities in improving the plasticity of Cu-Zr-Ag bulk amorphous alloys. In: Acta Materialia. 2018 ; Vol. 157. pp. 209-217.
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