3. Results and discussion
3.1. Particle characteristics and thermal analysis of the poreforming
agents
The morphology of the pore forming agent is known to affect
the ceramics mechanical and thermal properties, since it will
determine the shape of the voids produced by the porogen burning
out upon firing. Accordingly, the morphology of the spray-dried
powder and the wood residue was investigated by SEM. Fig. 1a
depicts the typical spherical shape of the spray-dried particles,
while Fig. 1b reveals the asymmetric shape and size distribution of
the wood residue particles. The sawdust fibres are mainly cylindrical
or elongated in form. EDS of the wood residue reveals the
presence of carbon and oxygen, and no additional element was
detected. For comparison, the EDS spectrum of the sp