The Ceramic Shell Mold Process

This process has largely replaced the original block or solid mold process except for some smaller high volume parts and for some aluminum casting where the mold is plaster bonded.

 

The ceramic shell mold technique involves dipping the entire cluster into a ceramic slurry, draining it, then coating it with fine ceramic sand. After drying, this process is repeated again and again, using progressively coarser grades of ceramic material, until a self-supporting shell has been formed. The shell may be from 3/16 to 5/8 in. thick.

 

The coated cluster is then placed in a high temperature furnace or steam autoclave where the pattern melts and runs out through the gates, runners and pouring cup. This leaves a ceramic shell containing cavities of the casting shape desired together with a suitable running and feeding system.