Journal of large-scale research facilities, 1, A6 (2015) http://dx.doi.org/10.17815/jlsrf-1-25 Published: 18.08.2015 STRESS-SPEC: Materials science di�ractometer Heinz Maier-Leibnitz Zentrum Technische Universität München Helmholtz-Zentrum Geesthacht, German Engineering Materials Science Centre Technische Universität Clausthal, Institute of Materials Science and Engineering Instrument Scientists: - Michael Hofmann, Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Garching, Germany, phone: +49(0) 89 289 14744, email: michael.hofmann@frm2.tum.de - Weimin Gan, German Engineering Materials Science Centre (GEMS) at Heinz Maier-Leibnitz Zentrum (MLZ), Helmholtz-Zentrum Geesthacht GmbH, Garching, Germany, phone: +49(0) 89 289 10766, email: weimin.gan@hzg.de - Joana Rebelo-Kornmeier, Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Garching, Germany, phone: +49(0) 89 289 14710, email: joana.kornmeier@frm2.tum.de Abstract: In response to the development of new materials and the application of materials and com- ponents in new technologies the direct measurement, calculation and evaluation of textures and resid- ual stresses has gained worldwide signi�cance in recent years. STRESS-SPEC, the materials science di�ractometer, which is jointly operated by the Technische Universität München, the Institute of Ma- terials Science and Engineering, Technische Universität Clausthal and by GEMS, Helmholtz-Zentrum Geesthacht, is located at the thermal beam port SR-3 of the FRM II and can easily be con�gured either for texture analysis or strain measurements. 1 Introduction The set-up utilises three di�erent monochromators: Ge (511), bent silicon Si (400) and pyrolitic graphite PG(002). This selection of monochromators and the possibility to vary automatically the take-o� angles from 2ΘM = 35º to 110º allows to �nd a good compromise between resolution and intensity for each measuring problem. The gauge volume de�ning optical system of primary and secondary slits is designed with regard to reproducibility of geometrical alignment and sturdiness. Both slit systems are linked to the sample table and the detector in such a way that the center of the beam remains the same under all condi- tions. Instead of the secondary slit a radial collimator can be used in front of the detector. Samples can be aligned using theodolites and a camera system. In addition, the possibility to scan surfaces of components o�ine using a CMM laser scanner is available at STRESS-SPEC. 1 http://jlsrf.org/ http://dx.doi.org/10.17815/jlsrf-1-25 https://creativecommons.org/licenses/by/4.0/ Journal of large-scale research facilities, 1, A6 (2015) http://dx.doi.org/10.17815/jlsrf-1-25 Figure 1: Instrument STRESS-SPEC (Copyright by W. Schürmann, TUM). 2 Typical Applications Residual stress analysis (Hofmann et al., 2006) • Industrial components • Welds • Superalloys • Strain mapping • Surface measurements from 150 µm possible (Šaroun et al., 2013) Texture determination (Brokmeier et al., 2011) • Global textures • Local textures • Strain pole �gures • FHWM pole �gures Structural applications • Phase transformation dynamics • Spatially resolved phase analysis (e.g. batteries) 3 Sample Environment • XYZ-table capacity 300 kg, Travel xy = ±120 mm, z = 300 mm, accuracy ∼ 10 µm • Load frame +/- 50 kN, heatable to 1000°C • Full circle Eulerian cradle (max. load 5 kg) • ¼ circle Eulerian cradle for heavy samples • Standard sample environment (e.g. furnace, cryostat) A positioning system consisting of a Stäubli-6-axes robotic arm for texture and strain measurements (payload up to 30 kg) can be mounted instead of the standard sample table (see Figure 2). It o�ers more �exibility than an Eulerian cradle and can be also used as automatic sample changer for texture measurements (Randau et al., 2015). 2 http://dx.doi.org/10.17815/jlsrf-1-25 https://creativecommons.org/licenses/by/4.0/ http://dx.doi.org/10.17815/jlsrf-1-25 Journal of large-scale research facilities, 1, A6 (2015) Figure 2: Robot at STRESS-SPEC holding a copper tube for combined texture and strain measurements. 4 Technical Data 4.1 Neutron beam • SR-3 thermal neutrons • Collimators (‘in-pile’) 15’, 25’, open 4.2 Monochromators • Ge(511), Si(400), PG(002) • 2ΘM 35° – 110° continuous • Wavelength 1 Å – 2.4 Å; (2.5 Å-1 < Q < 10.5 Å-1) 4.3 Possible slit size - Residual Stress • Primary slit: automatic continously variable up to 7 x 17 mm2 (W x H) • Secondary slit: continuously variable up to 15 mm • Radial collimators (FWHM = 1 mm, 2 mm, 5 mm, 10 mm) 4.4 Possible slit size – Textures • Primary slit: max. 30 x 40 mm2 (W x H) • Secondary slit: continuously variable up to 15 mm or open 4.5 Detector • 3He-PSD, 25 x 25 cm2; 256 x 256 pixel 3 http://dx.doi.org/10.17815/jlsrf-1-25 https://creativecommons.org/licenses/by/4.0/ Journal of large-scale research facilities, 1, A6 (2015) http://dx.doi.org/10.17815/jlsrf-1-25 Figure 3: Schematic drawing of STRESS-SPEC. References Brokmeier, H.-G., Gan, W., Randau, C., Völler, M., Rebelo-Kornmeier, J., & Hofmann, M. (2011). Tex- ture analysis at neutron di�ractometer STRESS-SPEC. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 642(1), 87 - 92. http://dx.doi.org/10.1016/j.nima.2011.04.008 Hofmann, M., Schneider, R., Seidl, G., Rebelo-Kornmeier, J., Wimpory, R., Garbe, U., & Brokmeier, H.-G. (2006). The new materials science di�ractometer STRESS-SPEC at FRM-II. Physica B: Condensed Matter, 385-386, Part 2, 1035 - 1037. (Proceedings of the Eighth International Conference on Neutron Scattering) http://dx.doi.org/10.1016/j.physb.2006.05.331 Randau, C., Brokmeier, H., Gan, W., Hofmann, M., Voeller, M., Tekouo, W., . . . Schreyer, A. (2015). Improved sample manipulation at the STRESS-SPEC neutron di�ractometer using an in- dustrial 6-axis robot for texture and strain analyses . Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 794, 67-75. http://dx.doi.org/10.1016/j.nima.2015.05.014 Šaroun, J., Kornmeier, J. R., Hofmann, M., Mikula, P., & Vrána, M. (2013, Jun). Analytical model for neutron di�raction peak shifts due to the surface e�ect. Journal of Applied Crystallography, 46(3), 628–638. http://dx.doi.org/10.1107/S0021889813008194 4 http://dx.doi.org/10.17815/jlsrf-1-25 http://dx.doi.org/10.1016/j.nima.2011.04.008 http://dx.doi.org/10.1016/j.physb.2006.05.331 http://dx.doi.org/10.1016/j.nima.2015.05.014 http://dx.doi.org/10.1107/S0021889813008194 https://creativecommons.org/licenses/by/4.0/ Introduction Typical Applications Sample Environment Technical Data Neutron beam Monochromators Possible slit size - Residual Stress Possible slit size – Textures Detector