The Investment Casting Process
Channel: The Federal Group USA
Date: 2022-02-21

Investment casting is thousands of years old. “Investment” refers to the mold being filled or invested with metal. Investment casting was initially used to produce decorations, religious figures, and jewelry. 

Today, this process makes intricate parts for many industries with brilliant, smooth finishes out of solid and corrosion-resistant metals.  Here are the steps:

1. Create the pattern. The pattern defines the geometry of the finished part. It’s made of wax. Typically the wax is molded in a metal die created using a 3D CAD model. But, for very short runs, we can machine the wax directly.

2. Build the tree. We attach several wax patterns to a wax rod to create a tree structure.

3. Make the shell. We dip the tree into a ceramic slurry and allow it to dry. Several dipping and drying cycles are used to build a robust ceramic shell for the rest of the process.

4. Remove the wax. The shell is turned upside down and heated. The wax runs out (that’s why it’s sometimes called lost wax casting). Then the shell goes into a high-temperature furnace to burn off any remaining wax and to strengthen the shell.

5. Cast the metal. Molten metal is poured into the shell. The tree we built in the second step defines where the metal goes. Now a metal part exists where each pattern used to be.

6. Remove the shell. The ceramic shell is broken away, leaving the tree structure—now only of metal.

7. Finish the parts. Parts are carefully cut from the metal tree structure. These parts are ground, polished, and machined into the final form.

8. Inspect the parts. Dimensional inspection and non-destructive testing (NDT) are performed to guarantee conformance to all required specifications.

Invest in your future. Learn more…
Whether you’re exploring options for a new product or you have an existing product that you’d like to put into production, The Federal Group USA can help you with your next stainless steel investment casting project. We’ve provided high-quality metal fabrication services to a wide variety of industries for more than 40 years. Contact us today to request a quote.

https://www.tfgusa.com/capabilities/investment-casting/