Characterization of pore space using “Wood`s metal”
Pores and holes in porous materials can be characterized by intrusion of alloys such as „Wood`s Metal“ (50 Bi, 25 Pb, 12.5 Sn and 12.5 Cd in wt%; melting point of 78°C) or „Rose`s metal“ (50 Bi, 25 Pb, 25 Sn in wt%; melting point of 94°C). At a pressure of 550 bar connective pores with equivalent diameters as small as 20 nm are intruded with the molten alloy. Sample size of 5 mm; temperatures typically up to 120°C. After cooling polished sections are prepared and analyzed using an electron microscope.
The method yield supplementary information to Hg-porosimetry and tomography. Pathway for fluids in rocks and other ceramic materials can be determined.
Dultz, S., Behrens, H., Simonyan, A., Kahr, G., Rath, T. (2006): Determination of porosity and pore connectivity in feldspars from soils of granite and saprolite, Soil Science 171 (9) , pp. 675-694