Solid bodies obtained by sintering glass microspheres
through the first stage of sintering have the useful characteristics of
large porosity combined with adequate mechanical strength. Additionally, if
the microspheres all have the same diameter, the pore morphology is well
defined in terms of shape and has a narrow distribution in size parameters.
The two major areas of application of the porous bodies are: A. light weight
but mechanically strong objects, and B. filtration of liquids. The fracture
strength and the specific liquid permeability of these bodies are expressed
as empirical functions of volume porosity (ratio of empty volume to the
total volume). Here, we describe the results of our systematic study of the
geometrical properties like density, linear contraction and global porosity
parameter φ,
and the flow parameter, the permeability coefficient as a
function of the sintering conditions. Our analysis shows that the existing
relations, property versus φ,
that claim to describe the behaviour are not
adequate for our simple system. We think that the contact area between the
adjoining spheres is a better parameter to consistently describe a larger
set of the properties. Since, for the initial stage sintering of single
diameter spheres, the contact area and the pore size can be expressed as a
function of linear contraction, latter is a better universal parameter in
terms of which the regular features of the property variations can be
expressed.