Strain tomography of polycrystalline zirconia dental prostheses by synchrotron X-ray diffraction Alexander M. Korsunsky a,⇑ , Nikolaos Baimpas a , Xu Song a , Jonathan Belnoue a , Felix Hofmann a , Brian Abbey a , Mengyin Xie a , Jerome Andrieux b , Thomas Buslaps b , Tee Khin Neo c,d a Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK b ID15, ESRF, 6 Rue Jules Horowitz, Grenoble, France c Specialist Dental Group, Mount Elizabeth Medical Centre, 3 Mount Elizabeth, #08-08/08-10, Singapore 228510, Singapore d Faculty of Dentistry, National University of Singapore, 11 Lower Kent Ridge Road, Singapore 119083, Singapore Received 25 August 2010; received in revised form 25 December 2010; accepted 28 December 2010 Abstract Non-destructive, quantitative and precise determination of internal strain distributions within structural materials and components can be accomplished by only a few experimental techniques, amongst which diffraction of penetrating radiation (X-ray and neutron beams) plays a central role. However, due to the various limitations of these methods, the 2-D and 3-D mapping of internal strains within bulk cross-sections at a spatial resolution of 0.1 mm or better has long remained a challenge. The principle of “strain tomography” pro- posed by the present authors (an instance of broader “rich” tomography methodology) makes use of the reconstruction tomography technique widely employed in imaging applications. In the present paper we report successful practical implementation of this principle to the study of bending strains in sintered polycrystalline zirconia used in the fabrication of multi-unit fixed prosthetic dentures. The results demonstrate the power of the technique, and pave the way to wider application of this approach to cross-sectional strain mapping in complex-shaped components under various loading conditions. Ó 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. Keywords: Tomography; Diffraction; Synchrotron X-ray; Zirconia; Polycrystalline materials 1. Introduction X-ray and neutron scattering can make use of the supe- rior penetrating ability of these beams to access the interior (bulk) of materials and components, and of their capability to undergo diffraction by the crystal lattice planes and thus to provide an “atomic strain gauge” to measure the average elastic strains within the scattering volume. Many more techniques are available for the task pro- vided the region of interest concerns the sample surface, or a thin layer that is either supported by a substrate (as in the case of coatings) or is free standing (as in the case of films and transmission electron microscopy foils). How- ever, many situations arise, particularly in the context of biomedical, materials science or mechanical engineering studies, when the non-destructive determination of internal strain distributions becomes desirable, and penetrating radiation (or electromagnetic waves) must be employed. Over the last two decades the use of diffraction of pene- trating radiation for strain determination has undergone rapid development. This is associated with a broad range of factors, including the availability of sources and instru- ments, focusing optics and better detectors. Many impor- tant developments took place at neutron diffraction facilities, particularly at spallation sources, making use of time-of-flight arrangements. Since large portions of 1359-6454/$36.00 Ó 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.actamat.2010.12.054 ⇑ Corresponding author. E-mail address: alexander.korsunsky@eng.ox.ac.uk (A.M. Korsunsky). www.elsevier.com/locate/actamat Available online at www.sciencedirect.com Acta Materialia xxx (2011) xxx–xxx Please cite this article in press as: Korsunsky AM et al. Strain tomography of polycrystalline zirconia dental prostheses by synchrotron X-ray diffraction. Acta Mater (2011), doi:10.1016/j.actamat.2010.12.054