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

Journal Article · Mon Jan 03 04:00:00 EST 2005 · Acta Materialia

DOI:https://doi.org/10.1016/j.actamat.2004.09.010· OSTI ID:20637110

Lee, Jae-Chul ^[1]; Kim, Yu-Chan ^[2]; Ahn, Jae-Pyoung ^[2]; Kim, Hyoung Seop ^[3]

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1. Division of Materials Science and Engineering, Korea University, Anamdong, Sungbuk, Seoul 136-701 (Korea, Republic of)
2. Advanced Metals Research Center, Korea Institute of Science and Technology (KIST), P.O. Box 131, Cheongryang, Seoul 130-650 (Korea, Republic of)
3. Department of Metallurgical Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

We developed the (Cu{sub 60}Zr{sub 30}Ti{sub 10}){sub 0.95}Ta{sub 5} 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 (Cu{sub 60}Zr{sub 30}Ti{sub 10}){sub 0.95}Ta{sub 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.

• OSTI ID: 20637110
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 1 Vol. 53; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPRESSION
COPPER COMPOUNDS
CRACK PROPAGATION
CRYSTALLIZATION
DEFORMATION
FINITE ELEMENT METHOD
FRACTURES
METALLIC GLASSES
PLASTICITY
PRESSURE DEPENDENCE
PRESSURE RANGE GIGA PA
SCANNING ELECTRON MICROSCOPY
SHEAR
STRAINS
TANTALUM COMPOUNDS
TITANIUM COMPOUNDS
TRANSMISSION ELECTRON MICROSCOPY
ULTIMATE STRENGTH
ZIRCONIUM COMPOUNDS