Comparing Investment Casting and Lost Foam: Everything you Need to Know

The lost foam process is extremely similar to the investment casting process, sometimes leading to confusion between the two. Lost foam is essentially the same process as investment casting, except that that patterns are created using expanding polystyrene foam instead of wax.

There are also some differences in the shell building process. Many of the benefits of investment casting can also be attributed to lost foam; however, tooling and processing costs make the process more prohibitive with little to no additional benefit.

As such, investment casting is the much more popular choice for production.

Investment Casting Advantages

• Can be used to cast a wide variety of ferrous and non-ferrous alloys.
• Low volume production runs are cheaper as tooling is less costly in comparison to other metal forming techniques.
• Investment casting can produce much more complex designs, incorporating design features such as logos.
• Parts require little machining after finishing.
• Excellent surface finishes can be achieved.

Lost Foam Advantages

• Can be used to cast a wide variety of ferrous and non-ferrous alloys.
• Parts require little machining after finishing.
• Can produce much more complex designs, incorporating design features such as logos.

Investment Casting Disadvantages

• Cycle times are much longer due to the nature of the process.
• Part size is limited by what can be securely gated to a tree.
• Dimensional accuracy is diminished with increasing part size.

Lost Foam Disadvantages

• Processing costs are higher due to scrap costs, shell building, and pattern handling.
• Surface finish is typically of lower quality.
• Tooling cost is increased.