Three-dimensional FIB/EBSD characterization of irradiated HfAl{sub 3}-Al composite

Conference · Fri Jul 01 00:00:00 EDT 2016

OSTI ID:22765238

Hua, Z.; Ban, H. ^[1]; Guillen, D. P. ^[2]; Harris, W. ^[2]

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1. Utah State University, Logan, UT (United States)
2. Idaho National Laboratory, Idaho Falls, ID (United States)

A thermal neutron-absorbing composite comprised of 28.4 vol.% HfAl{sub 3} intermetallic particles in an Al matrix, developed for use in a conduction-cooled thermal neutron filter, will enable fast flux irradiation of materials and fuels in an existing pressurized water test reactor. In this paper, an EBSD-FIB characterization approach is used to observe the microstructural changes of the HfAl{sub 3}-Al composite in response to simulated long-term neutron irradiation. Using a focused ion beam (FIB), the sample was fabricated to 25 μm x 25 μm x 20 μm and mounted on a transmission electron microscopy (TEM) grid. A series of operations were carried out repeatedly on the sample's top surface to prepare it for scanning electron microscopy (SEM). First, a ∼ 100-nm layer was removed by high voltage FIB milling. Then, several cleaning passes were performed on the newly exposed surface using low voltage FIB milling to improve the SEM image quality. The surface was then scanned by Electron Backscattering Diffraction (EBSD) to obtain a two-dimensional image. After 50 to 100 two-dimensional images were collected, the images were stacked to reconstruct a three-dimensional model using DREAM.3D software. Two such reconstructed three dimensional models were obtained from samples of the original and post-irradiation HfAl{sub 3}-Al composite, from which the most significant microstructural change caused by neutron irradiation appears to be the size reduction of both HfAl{sub 3} and Al grains. Possible causes include thermal expansion and related thermal strain from thermal neutron capture. (authors)

• Research Organization: American Nuclear Society - ANS, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
• OSTI ID: 22765238
• Resource Relation: Conference: TOP FUEL 2016: LWR fuels fuels with enhanced safety and performance, Boise, ID (United States), 11-15 Sep 2016; Other Information: Country of input: France; 12 refs.; Related Information: In: TOP FUEL 2016 Proceedings| 1670 p.
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
ALUMINIUM
BACKSCATTERING
ELECTRON DIFFRACTION
GRIDS
IMAGES
INTERMETALLIC COMPOUNDS
ION BEAMS
IRRADIATION
MICROSTRUCTURE
MILLING
NEUTRON REACTIONS
SCANNING ELECTRON MICROSCOPY
SURFACES
TEST REACTORS
THERMAL EXPANSION
THERMAL NEUTRONS
THREE-DIMENSIONAL CALCULATIONS
TRANSMISSION ELECTRON MICROSCOPY
TWO-DIMENSIONAL CALCULATIONS