Measurement of the components of plastic displacement gradients in three dimensions

Soeren F. Nielsen; Felix Beckmann; Rasmus Brauner Godiksen; Kristoffer Haldrup; Henning F. Poulsen; John A. Wert

doi:10.1117/12.559641

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26 October 2004 Measurement of the components of plastic displacement gradients in three dimensions

Soeren F. Nielsen, Felix Beckmann, Rasmus Brauner Godiksen, Kristoffer Haldrup, Henning F. Poulsen, John A. Wert

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Proceedings Volume 5535, Developments in X-Ray Tomography IV; (2004) https://doi.org/10.1117/12.559641
Event: Optical Science and Technology, the SPIE 49th Annual Meeting, 2004, Denver, Colorado, United States

Abstract

A method for non-destructive characterization of plastic deformation in bulk materials is presented. The method is based on X-ray absorption microtomography investigations using X-rays from a synchrotron source. The method can be applied to materials that contain marker particles, which have an atomic number significantly different from that of the matrix material. Data were acquired at the dedicated microtomography instrument at beamline BW2 at HASYLAB/DESY, for a cylindrical aluminium sample containing W particles with an average particle diameter of 7 μm. The minimum detectable size of the maker particles is 1-2 μm with the present spatial resolution at HASYLAB. The position (x,y,z) of all the detected marker particles within 1 mm³ was determined as function of strain. The sample was deformed in stepwise compression along the axis of the cylinder. A tomographic scan was performed after each deformation step. After a series of image analysis steps to identify the centre of mass of individual particles and alignment of the successive tomographic reconstructions, the displacements of individual particles could be tracked as a function of external strain. The particle displacements are then used to identify local displacement gradient components, from which the local 3D plastic strain tensor can be determined. This allows us to map the strain components as a function of location inside a deforming metallic solid.

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Soeren F. Nielsen, Felix Beckmann, Rasmus Brauner Godiksen, Kristoffer Haldrup, Henning F. Poulsen, and John A. Wert "Measurement of the components of plastic displacement gradients in three dimensions", Proc. SPIE 5535, Developments in X-Ray Tomography IV, (26 October 2004); https://doi.org/10.1117/12.559641

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