TY - GEN
T1 - Structural effect on the plastic behavior in highly porous glasses
AU - Woignier, T.
AU - Hafidi Alaoui, A.
AU - Primera, J.
AU - Phalippou, J.
AU - Scherer, George
PY - 2010/2/5
Y1 - 2010/2/5
N2 - Silica aerogels have been studied with the objective of understanding the mechanical behavior of these extremely porous (pore volume higher than 85%) glassy materials. Elastic and plastic behaviors are investigated using Hg porosimetry. Because of the peculiar structure of these materials, Hg liquid cannot enter their porous network and consequently induces an isostatic pressure. Due to the high compliance of the solid network, under isostatic pressure aerogels display an irreversible shrinkage caused by plastic deformation. The magnitude of the plastic shrinkage and the increase of the associated mechanical properties depend on the different parameters (porosity, elastic properties and structural features). The structural features are followed by X Rays scattering. The irreversible compaction can be explained by siloxane bond formation between clusters constituting the porous materials, retaining the strained structure. The pore collapse mechanism is favored by the large pores structure and loose cluster structure (low fractal dimension). This densification process could offer a new way to synthesize porous glasses at room temperature.
AB - Silica aerogels have been studied with the objective of understanding the mechanical behavior of these extremely porous (pore volume higher than 85%) glassy materials. Elastic and plastic behaviors are investigated using Hg porosimetry. Because of the peculiar structure of these materials, Hg liquid cannot enter their porous network and consequently induces an isostatic pressure. Due to the high compliance of the solid network, under isostatic pressure aerogels display an irreversible shrinkage caused by plastic deformation. The magnitude of the plastic shrinkage and the increase of the associated mechanical properties depend on the different parameters (porosity, elastic properties and structural features). The structural features are followed by X Rays scattering. The irreversible compaction can be explained by siloxane bond formation between clusters constituting the porous materials, retaining the strained structure. The pore collapse mechanism is favored by the large pores structure and loose cluster structure (low fractal dimension). This densification process could offer a new way to synthesize porous glasses at room temperature.
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U2 - 10.4028/www.scientific.net/KEM.423.15
DO - 10.4028/www.scientific.net/KEM.423.15
M3 - Conference contribution
AN - SCOPUS:75649115727
SN - 0878493034
SN - 9780878493036
T3 - Key Engineering Materials
SP - 15
EP - 24
BT - Mechanical Properties of Solids XI
T2 - 11th Congress on Mechanical Properties of Solids 2008
Y2 - 9 September 2008 through 12 September 2008
ER -