Investment casting is a processing procedure where molten metal is cast into a mold by surrounding the used pattern with a slurry that sets at room temperature. Subsequently the expendable pattern is removed by heat.

Investment casting is also called lost-wax casting which is one of the oldest metal-forming techniques. Lost foam casting is a modern form of investment casting that eliminates certain steps in the process.
The process is commonly used for small castings. However, it has produced complete aircraft door frames, steel castings and aluminum castings. It usually costs more per unit than die casting and sand casting but with lower equipment cost. It is able to produce complicated shapes that would not be easy with die casting, though like that process, it requires little surface finishing and minor machining.

Investment casting is used in power generation and aerospace industries in order to produce turbine blades with different shapes and cooling systems. Blades that are produced by investment casting can include the following types of blades:

• Single-crystal(SX)
• Directionally solidified(DS)
• Equiaxed

Firearms manufacturers enjoy fabricating firearm receivers, hammers, triggers at a low price. Investment casting machining is also used in military, medical, automotive, commercial and other industries.

Investment casting offers high production rates and good surface finish with little machining especially for small and highly complex components. The drawbacks include the specialized equipment, costly refractories and binders, operations to make a mold and occasional minute defects.

With the help of the above-mentioned process charms, pendants, rings can be easily made. In this process the wax or plastic mold is used to create a piece of jewelery. The wax mold is first weighed in order to determine the amount of metal required to fill the mold. Later the mold is attached to a base and a flask is slipped over it. When the mold is already in the flask, investment plaster is mixed and put in a vacuum to extract all the bubbles out of it. Later it is poured into the flask and then it is left to dry and harden. It takes two hours at the most.

When the investment is dried the base and flask are removed. The piece is put into an oven to burn out the wax. Then a centrifuge is used to melt the metal into the investment mold. Last of all, the piece is cleaned by filing and polishing.

Thus, investment casting has penetrated into various industries and has been unrivalled since then.

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