When the sugar's volume percentage was set to 80%, a change
in pore morphology was noticed. From an initially ellipsoid shape
(resembling the sugar particle morphology) the pores became elongated
due to the pronounced coalescence of sugar particles during the
compaction stage. This pore agglomeration was observed for all mean
particle sizes of sugar used in this study due to the specific volume
space of the die used. Agglomeration of the space holder particles occurs
at higher porosities and leads to inhomogeneity in the density distribution
of copper powder, which can cause reduced foam efficiency in the
target application. Taking all the above into consideration, a volume
percentage of 72% was chosen for the sugar particles, yielding to a
final foam porosity of 65%.