Alignment of sample position and rotation during in situ synchrotron X‐ray micro‐diffraction experiments using a Laue cross‐correlation approach. Issue 5 (20th September 2019)

• Record Type: Journal Article
• Authors: Zhang, Chenglu; Zhang, Yubin; Wu, Guilin; Liu, Wenjun; Xu, Ruqing; Juul Jensen, Dorte; Godfrey, Andrew
• Is Part Of: Journal of applied crystallography. Volume 52:Issue 5(2019)
• Page Start: 1119
• Page End: 1127
• Publication Date: 2019-09-20
• Subjects: X‐ray micro‐diffraction -- differential aperture X‐ray microscopy -- DAXM -- in situ deformation -- sample alignment -- digital image correlation -- DIC; Crystallography -- Periodicals; 548.05
• DOI: 10.1107/S1600576719010562
• Languages: English
• ISSNs: 0021-8898

Abstract

Abstract : A method is described for maintaining sample alignment to a high accuracy during in situ X‐ray synchrotron investigations involving 3D mapping of crystal orientations, and application of the method to in situ deformation of samples of fine‐grain‐size aluminium is described. Abstract : Laue micro‐diffraction has proven to be able to reveal material properties at the sub‐grain scale for many polycrystalline materials and is now routinely available at several synchrotron facilities, providing an approach for nondestructive three‐dimensional probing of the microstructures and mechanical states of materials. However, for in situ experiments, maintaining the positioning of the sample throughout the experiment, to achieve a good alignment of the characterized volumes, is a challenging issue. The aim of the present work is to address this problem by developing an approach based on digital image correlation of focused‐beam Laue diffraction patterns. The method uses small changes in the diffraction signal as a focused X‐ray beam is scanned over a surface region to allow corrections to be made for both sample lateral movement and rotation. The method is demonstrated using a tensile deformation experiment on an Al sample with 2.5 µm average grain size. The results demonstrate an accuracy of 0.5 µm for sample position registration and a precision in sample rotation of ∼0.01°. The proposed method is fast to implement and does not require the use of additional surface markers.