Shell molding and investment casting are two different casting processes used to create precise and intricate metal parts.
Shell molding, also called shell mold casting, is a casting process in which a resin-coated sand shell is heated and then removed from a pattern to create a cavity for the molten metal to be poured in. The shell is made by heating a metal pattern, in which it is coated with a layer of sand and resin mixture. After the mixture dries, the excess material is removed and the resulting shell is heated to a higher temperature to cure the shell and to remove all moisture. The molten metal is then poured into the shell to create the final casting. Shell molding is known for its high precision and smooth finish. It is commonly used for manufacturing parts in the automotive and aerospace industries.
Investment casting, also called lost wax casting, is a casting process used to create intricate metal parts with fine detail and accuracy. In the investment casting process, a wax or plastic pattern of the final part is created, and coated with a ceramic material to form a mold. The ceramic mold is heated to remove the wax, and then the molten metal is poured into the mold. The metal solidifies and the casting is removed from the mold. Investment casting is commonly used to produce parts in the aerospace, medical, and jewelry industries.
The main difference between shell molding and investment casting is in the materials used to create the mold. Shell molding uses a resin-coated sand shell, while investment casting uses a ceramic mold made from a wax or plastic pattern. Shell molding is generally faster than investment casting, but investment casting is capable of producing more intricate and highly accurate parts. Shell molding is typically used for larger parts with more simple geometry, while investment casting is better suited for smaller, more complex parts.