MOULD CASTING

There is a wide variety of casting processes. Selection of the right one for a given application depends upon the kind of alloy, required quality of precision, required mechanical properties, minimum wall thickness, size and weight of the casting, volume of production and availability of the processes. Besides the accuracy of individual dimensions, the quality of precision encompasses the surface finish and general appearance. Naturally, the key criterion for the right casting process selection is the final price of the castings in compliance with customer requirements.

The existing standard mould casting methods can be divided into three groups. The first group includes the gravity casting methods where only the gravitational force acts on the melt during casting. The second group of methods utilises increased forces onto the liquid metal during mould filling. The third group includes less conventional casting processes.

Gravity casting processes:

• Gravity casting in stationary moulds,
• Continuous casting,
• Tilt casting.

Casting processes at increased forces:

• High pressure die casting,
• Low pressure casting,
• Counter pressure casting,
• Vacuum pressure casting,
• Centrifugal casting.

Special casting processes:

• Squeeze casting,
• Vacuum melting and casting,
• Spin casting,
• Slush casting,
• Semi-solid metal casting.