Radiation induced effects on mechanical properties of nanoporous gold foams

Journal Article · Mon Jun 09 00:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4882275· OSTI ID:22300035

Wang, Y. Q.; Martinez, E.; Caro, A. ^[1]; Mook, W. M.; Sheehan, C.; Baldwin, J. K. ^[2]

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1. Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2. Center for Integrated Nanotechnology, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

It has recently been shown that due to a high surface-to-volume ratio, nanoporous materials display radiation tolerance. The abundance of surfaces, which are perfect sinks for defects, and the relation between ligament size, defect diffusion, and time combine to define a window of radiation resistance [Fu et al., Appl. Phys. Lett. 101, 191607 (2012)]. Outside this window, the dominant defect created by irradiation in Au nanofoams are stacking fault tetrahedra (SFT). Molecular dynamics computer simulations of nanopillars, taken as the elemental constituent of foams, predict that SFTs act as dislocation sources inducing softening, in contrast to the usual behavior in bulk materials, where defects are obstacles to dislocation motion, producing hardening. In this work we test that prediction and answer the question whether irradiation actually hardens or softens a nanofam. Ne ion irradiations of gold nanofoams were performed at room temperature for a total dose up to 4 dpa, and their mechanical behavior was measured by nanoindentation. We find that hardness increases after irradiation, a result that we analyze in terms of the role of SFTs on the deformation mode of foams.

• OSTI ID: 22300035
• Journal Information: Applied Physics Letters, Vol. 104, Issue 23; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATOMIC DISPLACEMENTS
COMPUTERIZED SIMULATION
DEFECTS
DISLOCATIONS
FOAMS
FORECASTING
GOLD
HARDNESS
IRRADIATION
MECHANICAL PROPERTIES
MOLECULAR DYNAMICS METHOD
NANOSTRUCTURES
NEON IONS
PHYSICAL RADIATION EFFECTS
POROUS MATERIALS
STACKING FAULTS
SURFACES
TEMPERATURE RANGE 0273-0400 K