Hello to everyone.
I need some about sterling silver melting and pouring in
an investment casting process (gypsum moulds), in order to cast
rings.
I’ve been using aluminium alloys for industrial purposes and now I
have to cast sterling silver. I’m completely new in this field. I
made a couple of trials with this procedure, as first approach:
-
a button and a central sprue (10 mm x 3 mm diameter) for each ring
(2 cylinders). -
SiC crucible, electric oven
-
metal pouring at 980 C in a vacuum machine
-
mold temperature 500 C
I noticed a considerable amount of shrinkage: castings showed a
partial filling, due to an incorrect solidification (I obtained only
the lower part of the rings, those connected to the sprue). I think
I’m not accostumed to work with this material and I obviously made a
mistake (or more…).
Any suggestion is welcome.
Thank you very much.
Marco