What Is Investment Casting?

Investment Casting (also known as lost wax casting or cire perdue) is the most common metalworking manufacturing process for complex-shaped metal parts with tight tolerances and superior surface finishes. It is a versatile casting process that can be used for a wide range of products, including turbine blades, medical equipment, firearm components, jewelry, golf club heads and many other machine components.

The most important advantage of investment casting is its ability to produce extremely precise and flawless parts. This is largely because of the high temperature that we use to melt out the wax.
Besides the benefits of investment casting, this process is also one of the most cost-effective and time-efficient methods for creating precision metal components. This is due to its ability to provide net shape or near-net shape castings, which can save customers significant amounts in material, labor, and machining costs.
To achieve these goals, a wax pattern is made, which is then dipped into a ceramic slurry. The slurry is a mixture of colloidal silica and alumina that helps the metal to bond to the wax and form a solid shell.

This shell is then heated in a furnace to melt out the wax and to allow the metal to be poured into it. Once the molten metal is in the shell, it’s then allowed to cool and solidify until the part is ready to be removed.
Because the wax patterns and ceramic molds are destroyed during the process, each casting requires a new wax pattern. As a result, each individual wax pattern must be precisely calculated to take into account the expected shrinkage of the wax pattern, the shrinkage of the ceramic shell, and the expected shrinkage of the metal casting itself.