System
description
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2019-10-16
4
–20
Platin
Set heating power to 3.5 kW (100%).
Use the special ceramic crucible for Platinum.
Put metal into the (cold) cruci-
ble. Push “Start” once for heating, set in flask and lock chamber. Push “Start”
second time to start the vacuum.
Full vacuum is reached inside the gypsum in about 30 seconds (see timer).
After metal is melted totally, wait for max. 8 seconds and cast. This will extend
the life time of the crucible!
Adjust your process in that way, that in the moment of pouring out the Pt. and
the end of evacuation time (at least 30 seconds) of the flask are concurrently.
Important hint:
Pt., melted in a standard Pt.-crucible, is absorbing silicate out of the crucible
material. As more often you re-melt same batch of metal, as more silicate will
be absorbed. This makes Pt. brittle.
Help: Coating of the inside of the crucible by use of liquid zircon oxide!
After casting: leave flask under set parameters for approx. 240 seconds.
Cobalt-
chromi-
um,
steel
alloys
Set heating power to 2.8 kW (80%).
Use the ceramic crucible for steel.
Put in crucible
, set in flask. Push “Start” twice to start heating and vacuum. If
full vacuum is there for at least 30 seconds (see timer) increase heating power
to 3.5 kW (100 %) and cast when metal is ready.
One more problem of NiCr, CoCr and steel alloys: some alloys tend to splash
in melted condition and under vacuum. In this case, it is useful to change set-
ting of melting pressure to -0.80 bar.
