- First class
quality for more than 100 years
Instructions for the correct use of MARS Graphite and Silicon Carbide
|New ceramic crucibles must be
brought to working temperature before their first use, i.e. whilst still
empty. MARS ISOMELT / MARS uniCstar crucibles should be
heated-up quickly to red heat.
Contrary to that MARS GLOBAL Graphite crucibles must be heated-up slowly
dark red heat and then quickly to bright red heat.
|Tongs, carrying clamps etc
must be constructed in such a way, that the jaws evenly fit around the
circumference of the crucible and thus avoid uneven pressure.
|Do not wedge the material
into the crucible! Take care that there is always a little space left
between the metal and the wall of the crucible, so that the material can
expand during heating. The coefficient of expansion of the metal is
higher than that of the crucible material.
|Ingots and larger pieces of
metal should be preheated if possible, and then placed carefully into
the crucible with tongs. Pieces must never be dropped into the crucible!
|The crucible has to be
emptied completely every night. No metal residues must be allowed to
freeze in the crucible.
|Take care that the crucible
is always full of metal, otherwise the upper part of the walls can
oxidize and this may result in cracks.
|When using fluxes, be careful
that these do not have direct contact with the crucible material.
Pouring should be done shortly after the fluxes have been added. Never
|As soon as the metal has
reached pouring temperature, casting should be done immediately.
Otherwise the life of the crucible may be reduced.
|When casting is finished,
every slag adhering to the inner surface must be removed, whilst the
crucible is still hot. This cleaning process must be done carefully,
avoiding any damage to the crucible material. Use suitable cleaning