VACUUM VS. CENTRIFUGAL CASTING
Casting methods are usually chosen on the basis of production
quantities and operation costs. Large production casters usually
employ vacuum assist techniques due to the large number of parts
that may be cast per melt.
THE ADVANTAGES OF VACUUM ASSIST CASTING ARE:
- High production rates.
- Control of molten metal and their oxides.
- Uniformity of metal supply.
THE DISADVANTAGES OF VACUUM ASSIST CASTING ARE:
- Higher flask temperature required.
Centrifugal techniques are also employed by many casters.
THE ADVANTAGES OF CENTRIFUGAL CASTING ARE:
- Higher initial velocity rate of the metal.
- Equipment costs are usually lower.
- Lower flask temperatures required.
THE DISADVANTAGES OF CENTRIFUGAL CASTING ARE:
- Lack of control of pouring, which allows oxides to be thrown
in with molten metal.
- Uneven solidification rate.
Centrifugal casting will generally yield higher rejection rates
due to the uneven solidification of the metal. This is seen as a
shrinkage type of porosity in the4-6 o'clock position in the flask.
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