Aqueous electrophoretic deposition (EPD),
using a zircon, i.e., zirconium silicate (ZrSiO4) suspension,
has been investigated as an alternative to the conventional
slurry dip-coating process for producing the face-coat of
investment casting ceramic shell moulds. This is because
EPD has the potential to (a) increase dimensional tolerances
in the resultant casting, and (b) form a uniform facecoat
on the entire mould-surface of complex shell moulds,
including the small and/or complex cavities that are a
problem for conventional dip-coating. Part 1 of this work
addresses the formation of carbon-filled investment casting
wax composite electrode materials. A carbon black powder
and a micronised graphite powder were used as the alternative
fillers in a water-emulsified pattern wax, an unfilled
pattern wax and an unfilled runner wax. The runner wax
composites exhibited consistently higher resistivities for
both filler types and across the range of filler concentrations.
Electrical resistivities of 1200 and 240 X cm were
attained for the 16 vol% micronised graphite-filled and
carbon black-filled straight pattern wax composites,
respectively. The higher conductivity values associated
with the use of carbon black filler are attributed to its highsurface
area and hierarchical agglomerated structure.