Grain boundary effects on defect production and mechanical properties of irradiated nanocrystalline SiC

Journal Article · Tue May 15 04:00:00 EDT 2012 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4723648· OSTI ID:22038966

Enze, Jin; Lisha, Niu; Enqiang, Lin; Xiaoxiong, Song ^[1]

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1. AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084 (China)

Grain boundaries (GBs) are known to play an important role in determining the mechanical and functional properties of nanocrystalline materials. In this study, we used molecular dynamics simulations to investigate the effects of damaged GBs on the mechanical properties of SiC that is irradiated by 10 keV Si atoms. The results reveal that irradiation promotes GB sliding and reduces the ability of GBs to block dislocations, which improves the deformation ability of nanocrystalline SiC. However, irradiation causes local rearrangements in disordered clusters and pinning of dislocations in the grain region, which restrains its deformation. These two mechanisms arise from the irradiation effects on GBs and grains, and these mechanisms compete in nanocrystalline SiC during irradiation. The irradiation effects on GBs dominate at low irradiation doses, and the effects on grains dominate at high doses; the result of these combined effects is a peak ductility of 0.09 dpa in nanocrystalline SiC.

• OSTI ID: 22038966
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 10 Vol. 111; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY
ATOMIC DISPLACEMENTS
COMPUTERIZED SIMULATION
CRYSTALS
DISLOCATION PINNING
DISLOCATIONS
DUCTILITY
GRAIN BOUNDARIES
ION BEAMS
IRRADIATION
KEV RANGE
MOLECULAR DYNAMICS METHOD
NANOSTRUCTURES
RADIATION DOSES
SEMICONDUCTOR MATERIALS
SILICON CARBIDES
SLIP