Atomistic Explanation of Shear-Induced Amorphous Band Formation in Boron Carbide
- Creators
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An, Qi
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Goddard, William A., III
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Cheng, Tao
Abstract
Boron carbide (B_4C) is very hard, but its applications are hindered by stress-induced amorphous band formation. To explain this behavior, we used density function theory (Perdew-Burke-Ernzerhof flavor) to examine the response to shear along 11 plausible slip systems. We found that the (011 ¯ 1 ¯ )/⟨1 ¯ 101⟩ slip system has the lowest shear strength (consistent with previous experimental studies) and that this slip leads to a unique plastic deformation before failure in which a boron-carbon bond between neighboring icosahedral clusters breaks to form a carbon lone pair (Lewis base) on the C within the icosahedron. Further shear then leads this Lewis base C to form a new bond with the Lewis acidic B in the middle of a CBC chain. This then initiates destruction of this icosahedron. The result is the amorphous structure observed experimentally. We suggest how this insight could be used to strengthen B_4C.
Additional Information
© 2014 American Physical Society. Received 12 May 2014; Published 28 August 2014. This work was supported by the Defense Advanced Research Projects Agency (W31P4Q-13-1-0010, program manager, Judah Goldwasser). In addition some support was provided by the Army Research Laboratory under Cooperative Agreement No.W911NF-12-2-0022. We thank Dr. Wei-Guang Liu at Caltech for the useful discussions.Attached Files
Published - PhysRevLett.113.095501.pdf
Supplemental Material - SI-Jun18.docx
Supplemental Material - SI-Jun18.pdf
Files
Additional details
- Eprint ID
- 50233
- Resolver ID
- CaltechAUTHORS:20141007-113611671
- W31P4Q-13-1-0010
- Defense Advanced Research Projects Agency (DARPA)
- W911NF-12-2-0022
- Army Research Laboratory
- Created
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2014-10-07Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Other Numbering System Name
- WAG
- Other Numbering System Identifier
- 1067