PSI - Issue 74

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2025) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 74 (2025) 56–61

© 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under the responsibility of Libor Pantělejev Abstract New focusing 3-axis diffractometer set-up equipped with the bent-perfect-crystal (BPC) monochromator and analyzer with the sample situated in between which has offered the sensitivity in determination of strains ∆ d / d < 10 -4 in polycrystalline materials, has been introduced recently. The resolution determined by FWHM of the diffraction profiles is about one order of magnitude higher with respect to that of conventional 2-axis neutron strain/stress scanners. Therefore, the new set-up also offers the possibility of line profile analysis for relatively large irradiated gauge volumes and reasonable counting times, because the 3-axis set-up exploits focusing in real and momentum space simultaneously. The analysis is carried out by rocking the BPC analyzer, which provides the diffraction profile characterizing the sample. The neutron signal is registered by a point detector. In this case Titanium Grade 2 polycrystalline samples exposed to an external load by CONFORM-ECAP (C-E) and the Rotary Swaging (RS) were investigated. The influence of plastic deformation on the measured diffraction profiles is documented. © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer- review under the responsibility of Libor Pantělejev Keywords: Neutron diffraction; Bragg diffraction optics; polycrystalline materials; microstructure analysis. 1. Introduction The conventional neutron strain/stress scanners (see Fig. 1), which are in fact powder diffractometers equipped with a position sensitive detector (PSD), evaluate some existing variations of lattice spacing within a sample (see e.g. Noyan and Cohen (1987), Hutchings and Krawitz (1992)). The required spatial resolution is usually of the order of millimeters and is determined by the dimensions of the gauge volume. However, for a very small gauge volume, detector signal becomes too small and thus the measurement is impractical. The strain/stress scanner is usually Eleventh International Conference on Materials Structure and Micromechanics of Fracture Investigation of titanium grade (Ti-Gr) polycrystalline samples by high-resolution three-axis neutron diffractometer Pavol Mikula a , Gergely Németh a , Gergely Farkas a , Michal Duchek b , David Hradil b , Kostyantyn Tuharin a,c and Vasyl Ryukhtin a a Nuclear Physics Institute CAS, 250 68 Řež, Czech Republic b COMTES FHT a.s., Průmyslová 995, 334 41 Dobřany, Czech Republic c Faculty of Mathematics and Physics, Charles University, Prague 121 16, Czech Republic

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer- review under the responsibility of Libor Pantělejev

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under the responsibility of Libor Pantělejev 10.1016/j.prostr.2025.10.034