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EXCEL and HIMELT crucibles
DESCRIPTION
EXCEL and HIMELT are high quality carbon-bonded silicon
carbide crucibles manufactured using the latest rollerforming techniques and are designed to cater for a range of
non-ferrous melting applications.
APPLICATIONS
EXCEL: Intended for aluminium melting in oil-fired furnaces,
melting copper-based alloys in gas and oil-fired furnaces,
melting precious metals and non-ferrous alloys in low to
medium frequency induction furnaces.
HIMELT: Provides enhanced performance in those
applications where more arduous service conditions exist.
TYPICAL METAL CASTING TEMPERATURE
EXCEL:t 850—1250ºC t
HIMELT:t 1000—1400ºC t

(1562—2280ºF)
(1830—2550ºF)

PERFORMANCE CHARACTERISTICS
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Fast melting speed through high consistent thermal tt
conductivity.
Excellent thermal shock resistance.
High resistance to oxidation.
Good erosion resistance.
Good resistance to corrosive attack by chemical tt
treatment agents.

IDENTIFICATION
EXCEL crucibles are coloured dark red and utilise the code
X. e.g. AX800. HIMELT crucibles are bright red and utilise the
code HM e.g. AHM800.
PATTERN RANGE
EXCEL and HIMELT crucibles are available in a comprehensive
range of shapes and sizes to suit most end user requirements.
Custom sizes can be supplied by special request. Heavy wall
(HW) versions can be supplied for increased life in arduous
applications and a selection of fixed pouring spouts with
optimised profiles is offered where required.
EXCEL and HIMELT crucibles can be supplied with Morganite’s
unique PD coating system, which can assist with metal cleanliness and prevention of dross adhesion.
QUALITY
EXCEL and HIMELT crucibles are manufactured from
premium grade raw materials under an ISO 9001:2008 quality
management system.

MorganMMS is a business within the MEM Division
of The Morgan Crucible Company plc.

PREHEATING / FIRST USE
FUEL-FIRED FURNACES: Crucibles should be pre-heated
empty until they reach a uniform bright red colour (circa
900°C) in order to pre-condition the glaze. The pre-heating
time will depend on the size of the crucible.
In the case of large capacity crucibles and furnaces with
high output burners the rate of temperature rise should be
controlled in the initial stages to minimise thermal stress. The
typical time taken from ambient to red heat is up to 1 hour.
Avoid direct flame impingement on the crucible surface.
INDUCTION FURNACES: The heat-up procedure is dependant on furnace frequency, coil dimensions, and the resistivity
of the metal being melted. It is recommended where possible
to preheat the crucible empty. The power input rate should
initially be limited until the crucible becomes bright red over
its entire surface. The time taken to pre-heat will depend on
the size of the crucible, but is usually in the range 20 – 40
minutes. Once one third of the crucible is full of molten metal
the power can be increased to a higher level. Silicon carbide
crucibles absorb proportionally high levels of power from the
induction field. Care should be taken not to overheat the crucible. The actual maximum power setting should be assessed
from experience and will be dependant on the capacity of
the crucible. The appearance of the inside wall of the crucible
should be monitored for signs of over-heating and the power
reduced once the full charge is molten.
CHARGING
As soon as the crucible has been pre-heated as specified,
charge and melt immediately. Charge light scrap and returns
first in order to form a cushion for heavier material. Use tongs
to charge ingots and place large pieces and ingots vertically
allowing space for expansion. Only add flux once the metal
is molten and use the minimum quantity required to obtain
good metal quality.