The Investment Casting Process

Investment casting is a manufacturing process that involves pouring molten alloyed material into a ceramic mold containing a hollow cavity of the desired shape. As the material solidifies, it forms the casting, which is then broken away from the mold.

We implement the following steps when creating investment castings:

• Engineering Review: The first step begins with a thorough customer evaluation of the Design for Manufacturing (DFM).

• Mold Design/Build: Once the initial evaluation is complete, we precision-engineer a wax injection mold that can be used to produce wax patterns for the final part.

• Wax Pattern Production: The wax injection mold is brought to the wax room for injection and assembly. This step helps us determine the necessary production capabilities.

• Ceramic Mold Construction: We dip the wax tree into a ceramic slurry until it is completely enveloped in the material. The tree is then thoroughly coated in sand to create a shell that forms the first layer. The mold is then dried.

• De-Waxing: The shell containing the wax pattern is placed into an autoclave that uses steam heat and extremely high pressure to remove the wax.

• Foundry & Pouring: The mold is placed into a high-temperature oven set to approximately 1000 C (1832 F) for curing and to prepare it for accepting molten metal.

• Shell & Casting Removal: Once the metal has cooled, the ceramic mold shell is broken away. At this point, the casting(s) can be removed from the metal tree.

• Finishing: The part’s gate is often removed by machining or grinding after manufacturing. Investment castings utilize a ceramic mold that can produce a much smoother surface (averaging a 125 RA surface finish).