Residual Stress Analysis and Texture Diffractometer
The diffractometer is designed for strain and stress analysis for simple geometric samples as well as for industrial applications and heavy components of arbitrary shape. The diffractometer itself consists of two big omega circles (Ω and 2Θ) with a diameter of 800 mm and upon a translation table (xyz-direction) for sample positioning in vertical and horizontal direction. This set up is installed for handling heavy and/or large samples and components such as impellers or turbines with diameters of up to half a meter and loads up to 300 kg. A range of equipment for sample positioning is available, such as a closed Eulerian cradle for samples with weights of up to 5 kg. A second cradle for heavy samples (up to 50 kg) with the ability to tilt the samples up to 90° is used to measure three perpendicular sample orientations. Gauge volumes can be adjusted horizontally and vertically by a computer-controlled variable primary slit in a range from 0-10 mm and 0-20 mm respectively. Rapid data visualization as well as evaluation is performed by the specially designed software SteCa.
- Residual stress analysis on monocrystalline or polycrystalline materials and machine components
- In-situ residual stress analysis within industrial components during mechanical (up to 50 kN) or thermal loading (up to 2000 K)
- Investigation of local phase transitions
- Texture measurements using Eulerian cradles
Among the components that were investigated are crankshafts, impellers, pistons, cylinder heads, turbine blades, divertors and welds for example. Selected publications are:
- "Distortion Analysis in the Manufacturing of Cold-Drawn and Induction Hardened Components" - Hirsch, T. et al. (2013). Metall. Mater. Trans. A., doi: 10.1007/s11661-013-1952-z
- "Welding residual stress behavior under mechanical loading" - Farajian, M. (2013). Welding in the World, The International Journal of Materials Joining 57, 157-169, doi: 10.1007/s40194-013-0024-8
- "Key Properties of Ni-Mn-Ga Based Single Crystals Grown with the SLARE Technique" - Rolfs, K. et. al. (2012). Adv. Eng. Mater. 14, 614–635, doi: 10.1002/adem.201200065
- "The influence of quench sensitivity on residual stresses in the aluminium alloys 7010 and 7075" - Robinson, J.S. et. al. (2012). Mater. Charact. 65, 73-85, doi: 10.1016/j.matchar.2012.01.005
- "Validation of Bragg edge experiments by Monte Carlo simulations for quantitative texture analysis" - Boin, M. et. al. (2011). J. Appl. Cryst. 44, 1040-1046, doi: 10.1107/S0021889811025970
- "Thermal Cycling Stresses in W-Monofilament Reinforced Copper" - Schöbel, M. et. al. (2011). Adv. Eng. Mater. 13, 742-746, doi: 10.1002/adem.201000309
- "Neutron Bragg-edge-imaging for strain mapping under in situ tensile loading" - Woracek, R. et. al. (2011). J. Appl. Phys. 109, 093506/1-4, doi: 10.1063/1.3582138
- "Effects of surface roughness and training on the twinning stress of Ni-Mn-Ga single crystals" - Chmielus, M. et. al. (2010). Acta Mater. 58, 3952-3962, doi: 10.1016/j.actamat.2010.03.031
- "Double twinning in Ni-Mn-Ga-Co" - Rolfs, K. et. al. (2010). Acta Mater. 58, 2646-2651, doi: 10.1016/j.actamat.2009.12.051.
|Monochromator||Si (400), double focussing|
|Take off angle of monochromator||65°|
|Wave length||0.147 nm|
|Flux||~ 107 n/cm2/s|
|Range of scattering angles||35° ≤ 2Θ ≤ 110°|
|FWHM standard powder||~ 0.3 (at 2Θ= 70°)|
|Detector||Position-sensitive area detector 30 x 30 cm2|
|Resolution||Δd/d ≈ 1.4·10‐3|
|Sample to detector distance||600 to 1300 mm|
|Beam size at sample||max: 10 x 20 mm2|
|Maximum sample size||0.5 m diameter|
|Scan range||• 200 mm (sample position scans)|
• ~ 35° ≤ 2Θ ≤ 110° (peak position scans)
|Instrument options||• Texture option|
• variable slit systems
• Radial collimator
|Sample environment||• x-y-z table for max. 300 kg|
• Eulerian cradles
• Stress rigs (tension, compression, torsion)
|Software||SteCa, TVtueb (analysis), CARESS (instrument control)|
- Monochromator upgrade (2007): A set of perfectly bent Si (400) crystals providing a neutron wavelength of 0.1486 nm focusses on the sample. Thus the E3 has become faster and more adaptable to different types of measurement.
- Electronics upgrade (2011): New motor control system and detector electronics have been implemented providing a reliable and modular interface between instrument and the CARESS control software.
- Radial collimator (2012): An oscillating collimator secondary optic has been implemented to improve the instrument resolution, especially at interfaces.
- New Eulerian cradle and stress rig (2013): An open tilt stage to measure three perpendicular strain directions within one sample alignment has been installed. The same is possible with a new custom-developed stress rig for tension and compression experiments with loads of up to 50 kN.
- New motorized primary slit (2013): E3 is now equipped with a primary slit device to change the gauge volume without instrument re-calibration (in both vertical and horizontal directions).
- Laser scanner (2014): A new laser scanner system is to be implemented on E3 to make instrument (re-)calibration and sample alignment much faster and more precise.
The recent upgrade activities have significantly increased the range of applications on E3, have reduced the alignment time between different types of experiments and, thus, the use of neutron beamtime has become much more efficient.
Please also visit our department webpage for further information about E3 and our complementary suite of engineering materials diffractometers.
In order to apply for beamtime on E3 please visit our User Info website. We are looking forward to your experiment proposals.