Identification of strain fields in pure Al and hybrid Ni/Al metal foams using X-ray micro-tomography under loading

0466629 - ÚTAM 2017 RIV GB eng J - Journal Article
Fíla, T. - Jiroušek, O. - Jung, A. - Kumpová, Ivana
Identification of strain fields in pure Al and hybrid Ni/Al metal foams using X-ray micro-tomography under loading.
Journal of Instrumentation. Roč. 11, November (2016), č. článku C11017. ISSN 1748-0221. E-ISSN 1748-0221.
[International Workshop on Radiation Imaging Detectors /18./. Barcelona, 03.07.2016-07.07.2016]
R&D Projects: GA MŠMT(CZ) LO1219
Keywords : computerized tomography (CT) * computed radiography (CR) * inspection with x-rays * X-ray radiography and digital radiography (DR)
Subject RIV: JJ - Other Materials
Impact factor: 1.220, year: 2016
http://iopscience.iop.org/article/10.1088/1748-0221/11/11/C11017/meta;jsessionid=00BAD2D2C17907F1AF4F90CAFAB2A5D2.c1.iopscience.cld.iop.org

Hybrid foams are materials formed by a core from a standard open cell metal foam that
is during the process of electrodeposition coated by a thin layer of different nanocrystalline metals.
The material properties of the base metal foam are in this way modified resulting in higher plateau
stress and, more importantly, by introduction of strain-rate dependence to its deformation response.
In this paper, we used time-lapse X-ray micro-tomography for the mechanical characterization of
Ni/Al hybrid foams (aluminium open cell foams with nickel coating layer). To fully understand the effects of the coating layer on the material’s effective properties, we compared the compressive
response of the base uncoated foam to the response of the material with coating thickness of 50
and 75 m. Digital volume correlation (DVC) was applied to obtain volumetric strain fields of the
deforming micro-structure up to the densification region of the deforming cellular structure. The
analysiswas performed as a compressive mechanical test with simultaneous observation usingX-ray
radiography and tomography. A custom design experimental device was used for compression of
the foam specimens in several deformation states directly in the X-ray setup. Planar X-ray images
were taken during the loading phases and a X-ray tomography was performed at the end of each
loading phase (up to engineering strain 22%). The samples were irradiated using micro-focus
reflection type X-ray tube and images were taken using a large area flat panel detector. Tomography reconstructions were used for an identification of a strain distribution in the foam using digital volumetric correlation. A comparison of the deformation response of the coated and the uncoated foam in uniaxial quasi-static compression is summarized in the paper.
Permanent Link: http://hdl.handle.net/11104/0264897