Let’s explore investment casting and how FDM tooling can be employed in this distinctive process. Investment casting, also known as lost wax casting, is a centuries old process used to produce metal components with intricate geometries and precise details. In this process, molten metal is poured into a ceramic cavity, which is formed by a wax pattern. The wax pattern is dipped into a ceramic slurry, and then melted out once the ceramic shell hardens. Metal is poured into the shell and after cooling, the shell is broken and removed, revealing a finished end-use part.
The advantages to this process are great surface finish, high dimensional accuracy, endless shape potential, and the ability to fill very thin sections.
It is generally used in applications that have relatively low production quantities and changing product designs. Injection molds are typically used to form the wax patterns. However, since investment casting is used for intricate designs, these molds require complex core assemblies and can cause parting line flash.
In addition, lead times to produce these molds are approximately two months, with high costs ranging between $5,000 to $25,000.
A big problem for foundries is they cannot produce any castings until the wax mold is complete, so if complications are discovered, additional time and money must be invested. Fused Deposition Modeling provides an alternative method for producing investment casting patterns that can yield dramatic time and cost savings.
FDM makes it possible to produce a pattern, thus eliminating the need for mold production. It can also serve as a prototype to evaluate form and fit where the foundry can quickly provide customers with a part that represents the final casting. If flaws are discovered, the design can be quickly adjusted and reprinted. In addition, the strength of the FDM materials makes it possible to perform functional testing in an assembly.
As you can see, the design freedom of 3D printing allows for unlimited complexity with zero effect on cost. For more information on 3D printing and our line of Stratasys printers, please click the button below.