Characterization of Materials Using Neutron Imaging
Neutron imaging (NI) is a technique based on the attenuation of a neutron beam as it passes through a sample under study. The relationship between the intensity of the incident beam on the sample and the transmitted beam is governed by the Beer-Lambert law. Therefore, the attenuation experienced by the beam is primarily related to the attenuation coefficient (or macroscopic cross-section) Σ of the elements composing the sample and the local thickness of the sample. This allows for the study of the internal structure of a sample or a piece as well as compositional changes within it. Because neutrons interact with the nuclei of atoms, the attenuation experienced by a neutron beam is very different from that of X-rays (which interact with the electron cloud of the atom). Therefore, due to its greater penetration power, the information obtained by NI is different and complementary to that obtained using X-ray imaging.
Evolution of hydrogen content curves (ppm by weight) in a Zr-2.5%Nb (% by weight) sample during in-situ heat treatment at 300°C. Facility: ANTARES – FRM II.
Since light elements such as H, C, and O exhibit higher attenuations than most metals, NI is suitable for studying the redistribution of these elements in metal alloys. This makes this technique ideal for studying, for example, the degradation in the mechanical properties of Zr-based nuclear alloys due to the incorporation of H, a process that occurs during their service in a power reactor, or the study of composite materials that exhibit different materials, such as the deformation of sandwich panels made of Al honeycomb and Ti inserts bonded with an epoxy material.
This line of research focuses on the use of NI techniques applied to the study of H redistribution in nuclear alloys of interest and the characterization of the mesostructure of advanced materials, such as materials manufactured by additive manufacturing or composite materials.
Related Publications
- J. Carridondo, S. R. Soria, J.R. Santisteban, N. Kardjilov, M. Irribaren, C. Corvalán-Moya, Analysis of erbium diffusion in zirconium-niobium alloys using neutron imaging and laser-induced breakdown spectroscopy, Journal of Nuclear Materials, 549 (2021) 152869
- X.H. Li, S. Soria, W. Gan, M. Hofmann, M. Schulz, M. Hoelzel, H.G. Brokmeier, W. Petry, Multi-scale phase analyses of strain-induced martensite in austempered ductile iron (ADI) using neutron diffraction and transmission techniques, Journal of Materials Science 56 (2021) 5296-5306.
- S.R. Soria, X.H. Li, M. Schulz, M. Boin, M. Hofmann, Determination of martensite content and mapping phase distribution on Austempered Ductile Iron using energy-selective neutron imaging, Materials Characterization 166 (2020) 110453.
