P. Walsh et al., Amorphization and anisotropic fracture dynamics during nanoindentation of silicon nitride: A multimillion atom molecular dynamics study, APPL PHYS L, 77(26), 2000, pp. 4332-4334
Molecular dynamics simulations of nanoindentation of 10 million atom alpha
-Si3N4 films using a rigid indenter are reported. Local pressure distributi
ons and configuration images of the plastically deformed region are present
ed. Residual tensile pressures correspond to voids and cracks that separate
regions of compacted, plastically deformed material and elastically recove
red crystalline material. Structural analysis shows that pile-up material o
n the surface and deformed material under the indenter is amorphous. With t
his indenter geometry, Si3N4 deforms primarily by amorphization, which is a
rrested by cracking at the indenter corners and piling-up of material along
the indenter sides. Indentation fracture exhibits anisotropic behavior con
sistent with the orientation-dependent fracture toughness values. (C) 2000
American Institute of Physics. [S0003- 6951(00)01048-2].