Structure, mechanical properties, and dynamic fracture in nanophase silicon nitride via parallel molecular dynamics

Book · Mon Sep 01 04:00:00 EDT 1997

OSTI ID:522309

Tsuruta, K; Omeltchenko, A; Nakano, Aiichiro; Kalia, R K; Vashishta, P ^[1]

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1. Louisiana State Univ., Baton Rouge, LA (United States)

Million-atom molecular-dynamics (MD) simulations are performed to study the structure, mechanical properties, and dynamic fracture in nanophase Si{sub 3}N{sub 4}. The authors find that intercluster regions are highly disordered: 50% of Si atoms in intercluster regions are three-fold coordinated. Elastic moduli of nanophase Si{sub 3}N{sub 4} as a function of grain size and porosity are well described by a multiphase model for heterogeneous materials. The study of fracture in the nanophase Si{sub 3}N{sub 4} reveals that the system can sustain an order-of-magnitude larger external load than crystalline Si{sub 3}N{sub 4}. This is due to branching and pinning of the crack front by nanoscale microstructures.

• OSTI ID: 522309
• Report Number(s): CONF-961202--; ISBN 1-55899-361-4
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPUTERIZED SIMULATION
CRACKS
FRACTURE PROPERTIES
GRAIN SIZE
MECHANICAL PROPERTIES
MICROSTRUCTURE
ORDER PARAMETERS
POROSITY
SILICON NITRIDES
THEORETICAL DATA
YOUNG MODULUS