Role of Ultrafine Microstructures in Dynamic Fracture in Nanophase Silicon Nitride

Journal Article · Sat Mar 01 04:00:00 EST 1997 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.78.2144· OSTI ID:512725

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

---

1. Concurrent Computing Laboratory for Materials Simulations, Department of Physics and Astronomy and Department of Computer Science, Louisiana State University, Baton Rouge, Louisiana 70803 (United States)

Using 10{sup 6}-atom molecular-dynamics simulations, we investigate dynamic fracture in nanophase Si{sub 3}N{sub 4}. The simulations reveal that intercluster regions are amorphous, and they deflect cracks and give rise to local crack branching. As a result, the nanophase system is able to sustain an order-of-magnitude larger external strain than crystalline Si{sub 3}N{sub 4}. We also determine the morphology of fracture surfaces: For in-plane fracture surface profiles the roughness exponent {zeta}=0.57 and for out-of-plane profiles the exponents {zeta}{sub {perpendicular}}=0.84 and {zeta}{sub {parallel}}=0.75 are in excellent agreement with experiments. {copyright} {ital 1997} {ital The American Physical Society}

• DOE Contract Number: FG05-92ER45477
• OSTI ID: 512725
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 11 Vol. 78; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRACK PROPAGATION
FRACTURE MECHANICS
MICROSTRUCTURE
MOLECULAR DYNAMICS METHOD
ROUGHNESS
SILICON NITRIDES
SIMULATION
SOLID CLUSTERS
nanostructured materials