FN Archimer Export Format PT J TI In situ observation of syntactic foams under hydrostatic pressure using X-ray tomography BT AF LACHAMBRE, J. MAIRE, E. ADRIEN, J. CHOQUEUSE, Dominique AS 1:1;2:1;3:1;4:2; FF 1:;2:;3:;4:PDG-REM-RDT-LCSM; C1 Inst Natl Sci Appl, CNRS, UMR 5510, F-69621 Villeurbanne, France. IFREMER, Ctr Brest, Mat & Struct Grp RDTIMS, F-29280 Plouzane, France. C2 INSA LYON, FRANCE IFREMER, FRANCE SI BREST SE PDG-REM-RDT-LCSM IN WOS Ifremer jusqu'en 2018 copubli-france IF 3.94 TC 22 UR https://archimer.ifremer.fr/doc/00148/25926/26375.pdf LA English DT Article DE ;Syntactic foams;X-ray tomography;Hydrostatic compression test;Non-destructive testing;Synchrotron radiation AB Syntactic foams (hollow glass microspheres embedded in a polymeric matrix) are being used increasingly for the purpose of thermal insulation in ultradeep water. A better understanding of the damage mechanisms of these materials at the microsphere scale under such a hydrostatic loading condition is of prior importance in determining actual material limits, improving phenomenological modelling and developing novel formulations in the future. To achieve this goal, a study based on X-ray microtomography was performed on two syntactic foam materials (polypropylene and polyurethane matrix) and a standard foamed PP. A special set up has been designed in order to allow the X-ray microtomographic observation of the material during hydrostatic pressure loading using ethanol as the pressure fluid. Spatial resolution of (3.5 mu m)(3) and in situ non-destructive scanning allowed a unique qualitative and quantitative analysis of the composite microstructure during stepwise isotropic compression by hydrostatic pressure up to 50 MPa. The collapse of weaker microspheres were observed during pressure increase and the damage parameters could be estimated. It is shown that the microspheres which are broken or the porosities which are close to the surface in the foamed PP are filled by a fluid (either the ethanol or the polymeric matrix itself). The hydrostatic pressure decreases the volume of the foam only slightly. In the PU matrix, ethanol diffusion is seen to induce swelling of the matrix, which is an unexpected phenomenon but reveals the high potential of X-ray microtomographic observation to improve diffusion analysis in complex media. PY 2013 PD JUL SO Acta Materialia SN 1359-6454 PU Pergamon-elsevier Science Ltd VL 61 IS 11 UT 000320296300013 BP 4035 EP 4043 DI 10.1016/j.actamat.2013.03.017 ID 25926 ER EF