Enhanced plasticity in a bulk amorphous matrix composite: Macroscopic and microscopic viewpoint studies

Jae-chul Lee, Yu Chan Kim, Jae Pyoung Ahn, Hyoung Seop Kim

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106 Citations (Scopus)

Abstract

We developed the (Cu60Zr30Ti10) 0.95Ta5 amorphous matrix composite, which is a Cu-based bulk amorphous composite reinforced with a micron-sized Ta-rich crystalline phase. The composite demonstrated an ultimate strength of 2332 MPa with a dramatically enhanced fracture strain of 15.3%. Macroscopic observation of the fractured (Cu60Zr30Ti10)0.95Ta 5 amorphous composite using scanning electron microscopy showed the presence of multiple shear bands along with numerous secondary shear bands, which spread from the primary shear bands. On the other hand, microscopic observation of the fractured composite using transmission electron microscopy showed that the cracks propagate through the amorphous matrix in a jagged manner. The observed macroscopic and microscopic behaviors, involving shear band formation and crack propagation, are believed to be responsible for the enhanced plasticity. Finite element calculations using the Mohr-Coulomb model of hydrostatic pressure dependent materials were conducted, in order to gain a better understanding of various aspects of the macroscopic deformation behavior, such as the interaction of the shear bands with the crystalline particles, the initiation site of the shear bands, and the formation of multiple shear bands, while the microscopic deformation behavior was explained based on the formation of nanocrystallites that had precipitated under quasistatic compression.

Original languageEnglish
Pages (from-to)129-139
Number of pages11
JournalActa Materialia
Volume53
Issue number1
DOIs
Publication statusPublished - 2005 Jan 3

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Keywords

  • Bulk metallic glass
  • Composite
  • Deformation-induced crystallization
  • Mohr-Coulomb yield criterion
  • Shear bands

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Materials Science(all)
  • Metals and Alloys

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