XTMS Experimental Station
The X-ray Scattering and Thermo-Mechanical Simulation (XTMS) experimental station has been co-developed by the Metals Characterization and Processing group of the Brazilian Nanotechnology National Laboratory (LNNano) and the Brazilian Synchrotron Light Laboratory (LNLS) Engineering and Technical staff. Such installation, which is located at LNLS XRD1 beamline, is operated by LNNano with LNLS support. It consists of a diffraction beamline built around an advanced thermo-mechanical simulator, the Gleeble® Synchrotron system, which allows the material of interest to be submitted to a wide range of thermo-mechanical conditions with high accuracy and reproducibility. Linear or area X-ray detectors are mounted in a high-resolution goniometer for fast data acquisition, which allows time resolved measurements.
The thermo-mechanical simulation hutch is also equipped with the following auxiliary systems:
- Fluorescent beam blanker that acts as blanker and alignment reference.
- Fully motorized asymmetric slit system.
- Positioning table with two motorized axis, positioning the Gleeble in the normal plane to the beam.
- Split beam positioning monitor (XBPM) with photon current monitoring capabilities.
- Auxiliary systems such as monitoring cameras, one-color pyrometer, quench system and liquid nitrogen cooling system.
- Non-contact laser dilatometer.
The Thermo-Mechanical Simulator
The custom built Gleeble 3S50™ thermo-mechanical simulator controls the sample’s temperature, uniaxial stress/strain condition and tank’s atmosphere. For such, the sample is mounted within a chamber, which can be vacuum pumped or gas filled.
Heating is done by Joule effect, and power is controlled by a thermocouple welded to the interest area. Heating rates as high as 500 ºC/s are easily achieved and controlled. Cooling rates depend on sample design and other factors, but rates around 40 ºC/s are easily achieved for temperatures above 200 ºC when Cu jaws are used. In addition, LNNano has developed a liquid nitrogen cooling system which allows experiments at temperatures as low as -150 °C (sample material dependent) and cooling rates exceeding 50 °C/s. Maximum temperature is limited only by the sample melting temperature and thermocouple range, with a wide variety of thermocouples available for use.
Stress/strain are applied and controlled by the symmetric movement of the jaws. Force control is performed using a 44 kN load cell with 0.1 kN resolution. Strain can either be controlled through the jaws position or using a non-contact laser dilatometer, which can be used in low-resolution mode with ±10 mm range, in mid range mode with ±1.0 mm range or high-resolution mode with ±0.2 mm range. Tests are commonly done in vacuum, but other atmospheres can be used. Minimum pressure on the chamber is 10-3 Torr.
Diffraction Instrumentation Capabilities
The experimental station is equipped with a Heavy Duty Huber goniometer. The goniometer is mounted on a positioning table with movements on the x, y, and z directions, allowing reliable alignment between the goniometer turning axis and the sample illuminated spot. Linear and area detectors are mounted in a positioning table which moves along the goniometer arm, changing the detector distance to the sample.
The installation has two Mythen-1K detectors, which are fast (0.3ms readout time) and high efficiency x-ray detection systems with 50µm x 8mm pixel size assembled in 1280 pixels strips. In addition to these linear detectors, a 2D detector is also available. The Rayonix SX165 is an area high resolution detector with 39×39 µm2 pixel size, with a round active area of 165 mm diameter. Readout times depends on binning, ranging from 5 s at 1×1 to 0.8 s at 8×8. Detector distance from the sample ranges from 361 to 600 mm, allowing adjusting angular range and resolution.
Another CCD camera with macro optics is mounted on the goniometer arm for automated goniometer/sample alignment by digitally processing the images from the interest region of the sample taken at different 2θ angles.
Incident beam control is possible with an X-ray beam position meter and a high resolution slit system. Further control of beam size and position can be performed using the XRD1 beam line optical elements.
The thermo-mechanical simulator computer controls the sample’s programmed stress/strain and temperature, while a second computer controls the diffraction instrumentation and positioning. Experiments are programmed as sequential instructions for both systems and are synchronized by the dedicated SyncSim software. Within this Windows-based interface, the user defines the experimental steps, where the thermal, mechanical and data acquisition parameters can be set up independently.
Due to the complexity of this installation, we would like to ask the interested users to contact the developing team through beamline engineer Leonardo Wu (email@example.com) to discuss the experiments’ viability and level of technical support and possible scientific involvement that will assure successful experiments. During this post-commissioning stage the developing team will be deeply involved with selected users experiments and will initiate their training or future independent use.
This installation has been co-funded by the TMEC-Petrobras research network, FINEP, LNNano and LNLS.
How to use this installation?
To see more details about the submission process, go to guidelines to submit a proposal to XTMS.
Publications by Beamline Users
Ariza, E. A., Nishikawa, A. S., Goldenstein, H., Tschiptschin, A.P., “Characterization and methodology for calculating the mechanical properties of a TRIP-steel submitted to hot stamping and quenching and partitioning (Q&P)”, Materials Science and Engineering: A 671 (1 August 2016), 54-69. http://dx.doi.org/10.1016/j.msea.2016.06.038
Gauss, C., Souza Filho, I.R., Sandim, M.J.R., Suzuki, P.A., Ramirez, A.J., Sandim, H.R.Z., “In situ synchrotron X-ray evaluation of strain-induced martensite in AISI 201 austenitic stainless steel during tensile testing”, Materials Science and Engineering: A 651 (10 January 2016) 507–516. http://dx.doi.org/10.1016/j.msea.2015.10.110
Smith, R.T., Lolla, T., Gandy D., Wu, L., Faria, G., Ramirez, A.J., Babu, S.S., Anderson, P.M., “In-Situ X-ray Diffraction Analysis of Strain-Induced Transformations in Fe- and Co- base Hardfacing Alloys”, Scripta Materialia 98 (2015) 60-63. http://dx.doi.org/10.1016/j.scriptamat.2014.11.003