Publications
Amorphization-governed elasto-plastic deformation under nanoindentation in cubic (3C) silicon carbide
L. Zhao, M. Alam, J. Zhang, R. Janisch, A. Hartmaier.
Ceramics International, 46, 12470–12479, (2020)
Abstract
Amorphization plays an important role in ceramic deformation under mechanical loading. In the present work,
we investigate the elasto-plastic deformation mechanisms of monocrystalline cubic silicon carbide (3C–SiC) in
spherical nanoindentation by means of molecular dynamics simulations. The indentation-induced amorphization
and its interactions with other deformation modes are emphasized. Initially, the suitable empirical potential
capable of accurately characterizing the mechanical and defect properties of monocrystalline 3C–SiC, as well as
the propensity of phase transformation from 3C–SiC to amorphous SiC, is rationally selected by benchmarking of
different empirical potentials with experimental data and density functional theory calculations. Subsequently,
the inhomogeneous elastic-plastic transitions during nanoindentation of monocrystalline 3C–SiC, as well as their
dependence on crystallographic orientation, are investigated. Phase transformations including amorphization
are analyzed using combined methods based on radial distribution function and bond angle distribution. Our
simulation results demonstrate that before plasticity initiation-related “pop-in” event, each indented-mono-
crystalline 3C–SiC experiences a pure quasi-elastic deformation governed by the formation of amorphous
structures. And this process of amorphization is fully reversible for small indentation depths. Further amor-
phization and dislocation nucleation jointly dominate the incipient plasticity in 3C–SiC nanoindentation. It is
found that the indentation-induced defect zone composed of amorphous phase and dislocations is more pro-
nounced in 3C–SiC(010) than that in the other two orientations of (110) and (111).
Keyword(s): 3C–SiC; nanoindentation; plasticity; amorphization; molecular dynamics simulation
DOI: 10.1016/j.ceramint.2020.02.009
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