High resolution X-ray CT as enabling technology for material research

Transcription

1 High resolution X-ray CT as enabling technology for material research Veerle Cnudde Dept. of Geology & Soil Science - UGCT, Ghent University, Belgium With credits to the entire UGCT team (

2 Radiation Physics research group (Dept. of Physics and Astronomy) Prof. Dr. Luc Van Hoorebeke Dr. ir. Manuel Dierick Dr. ir. Matthieu Boone Dr. Bert Masschaele Drs. Jelle Dhaene Drs. ir. Thomas De Schryver Dra. Amelie De Muynck Ir. Pieter Vanderniepen Sedimentary and Engineering Geology (Dept. of Geology and Soil Science) Prof. Dr. Veerle Cnudde Dr. Hannelore Derluyn Dr. Victor Cardenes Dr. Jan Dewanckele Drs. Tim De Kock Drs. Marijn Boone (UGent/VITO) Drs. Wesley De Boever Drs. Tom Bultreys Drs. Jeroen Van Stappen Drs. Delphine Vandevoorde (UGent/UA) Danielle Schram Laboratory of Wood Technology (Dept. Forest and Water Management) Prof. Dr. ir. Joris Van Acker Dr. ir. Jan Van den Bulcke Drs. ir. Wanzhao Li UGCT : Centre for X-ray tomography

3 UGCT : Centre for X-ray tomography XRE Inside Matters

4 UGCT : Centre for X-ray tomography Perform research on and with high resolution X-ray CT Control and optimize complete workflow Hardware: custom designed and built CT scanners Hardware: peripheral equipment (climate chambers, pressure stage...) Software: scanner operation Software: tomographic reconstruction (Octopus) Software: 3D analysis (Morpho+/Octopus Analysis) Applied material research for the characterization of wood, stone, concrete, plastics, foams, food, metal, biological material,.)

5 What is X-ray micro-tomography?

6 (1991, John O Brien, the New Yorker Magazine)

7 Tomography: the principle X-ray source Sample I I 0 i i ) i E exp ( µ E x de X-ray detector

8 Tomography: the principle X-ray source Sample X-ray detector R d 1 1 M M s M SDD SOD R: Resolution d: resolution detector s: spot size X-ray source M: magnification

9 Dhondt et al, Trends in Plant Science 15(8): Boone et al., Geosphere. 7(1); Realisations by UGCT Van Vlierberghe et al., Biomacromolecules 8(2): Masschaele et al., NIMA 580(1): Van den Bulcke et al., International biodeterioration and Biodegradation. Dierick et al., NIMB 324:35-40.

10 Realisations by UGCT

11 HECTOR (2012) High power, high voltage directional tube (240kVp, 280W), focal spot size down to 4µm Large flat-panel detector (40²cm²) Fast scanning Source : directional open tube kv max : 240 kv P max : 280 Watts Focal spot : 4 µm (nominal) Sample stage : Rotational error : ~1µm Max. sample weight : 80 kg source-object range : ~2m vertical (helical)range :~1m Detector : Perkin Elmer asi flat panel FOV : 40cm x 40cm pixel count : 2000x2000 pixel pitch : 200 µm source-detector range : ~2m See also: B. Masschaele et al., J. Phys. Conf. Series. 463 (1), (2013)

12 HECTOR (2012)

13 Sample size Resolution Subsample A (4 µm resolution) discrimination of mineral grains and pore space Subsample B (2.8 µm resolution) discrimination between different minerals (quartz, feldspar, clays) Microporosity visible

14 EMCT (2012) Gantry based system Environmental control (Temperature, pressure,...) Continuous scanning Ultra-fast scanning (<30 sec) Maximum resolution 5µm Source : directional closed tube kv max : 130 kv P max : 39 Watts Focal spot : 5 µm (nominal) Sample stage : Rotational error : <3µm Max. sample weight : 50 kg source-object range : ~2m vertical (helical)range : ~1m Detector : CMOS flat panel pixel count : 1316x1312 pixel pitch : 100 µm source-detector range : 15-40cm Dierick et al., Nucl. Inst. & Meth. 324 (0), (2014)

15 X-ray CT add-on modules Pressure Cell (120 bar) Freezing Cell (-20 C) Climatic chamber Pressure/tensile stage

16 Acquiring, or developing extra add-on modules, such as an in-situ tensile/compression cell.

17 Image analysis: 3D pore/grain characterization - Porosity calculation - Labeling different pores according to: - size - orientation - surface - - Pore network extraction - Pore throats location and characteristics

18 Pore Network Modelling for multi-phase flow Mineral grains Pore space Prediction of macroscopical behaviour based on microscopical study (PNM)

19 Water displaced by non wetting phase

20 APPLICATIONS OF HIGH RESOLUTION X-RAY CT AS CHARACTERIZATION AND MONITORING TECHNIQUE

21 Salt precipitation migration into pores close to surface controlled by RH cycling (a) (c) Mšené sandstone + halite crystals (red) (a-b) after 1 st cycle of wetting and drying at 20%RH and (c-d) after 2 additional cycles. (b) (d)

22 Dynamic Imaging: climatic chamber How does salt crystallization looks like in 3D? 3 molal Na 2 SO 4 -solution from room t cooled to 0 C => sodium sulfate heptahydrate crystallization Scans taken continuously during 19 minutes at a rate of 1 scan/80 s (pixel size: 24 µm).

23 Monitoring internal changes due to external chemical changes Before acid test After 6 days Dewanckele, et al Materials Characterization 88:

24 Dynamic Imaging: freezing cell

25 Dynamic Imaging: wollastonite (CaSiO 3 ) carbonatation CO 2 B 18 scans in total Total period: 14 hours Each scan: 2 20 Resolution: 18 µm Total porosity: 42.5 % brine: 35.4% Semi-saturated conditions CO 2 : 7.1%

26 Dynamic Imaging: wollastonite carbonatation CO 2 Semi-saturated conditions CaCO 3

27 ~ 3.5 mm Chemical + structural info Currently a new scanner is under development: XRF-CT scanner Heracles => Combines micro-ct scanner with XRF detectors (detect characteristic radiation that comes from a sample being irradiated with X-rays => allowing to identify the elements in it). + + micro-ct 2D-µ-XRF SR-µ-XRF CT-µ-XRF Biotite magnetite Zircon

28 Conclusions: - HRXCT is an ideal 3D characterization technique - a wide range of new and dynamic experiments are now possible using lab-based HRXCT - spatial and temperal resolution are still increasing - besides on the hardware level, also on the software level progress is being made

29 Thank you for your attention! Prof. Dr. Veerle Cnudde Special thanks to: Entire UGCT team SEPOCOM SECEMIN ISHECO VITO Department of Geology and Soil Science - UGCT, Ghent University, Krijgslaan 281/S Ghent Belgium