Lost Foam Casting
ChinaSavvy, a Western-owned and managed industrial casting company based in China, specializes in the Lost Foam Casting process, delivering high quality castings that meet your exact standard requirements.
Invented in 1964 by M.C. Flemming, this casting process is an effective production option for large volume parts that require a good surface finish and tight tolerances.
Lost Foam Casting, or evaporative mold casting, has both its advantages and disadvantages, influenced by a number of factors, including:
- The type of material that can be used in the process, the pattern itself as well as the mold.
- The cost of the lost foam casting supplies. An example of this would be the cost involved in producing the mold and the pattern.
- Amount of material that is needed throughout the entire metal casting process. This includes the material needed for the cast itself as well as the material needed for processes further down the production line.
- The volume of the casts that needs to be produced by the foundry in the process.
- Energy required to efficiently complete the lost foam casting process as well as the cost per unit to be produced.
The Advantages of Lost Foam Casting
The lost foam casting process enables foundries to produce complex castings - casting that would normally require cores. Furthermore, this metal casting process is capable of delivering dimensionally accurate castings with an excellent as-cast surface finish.
No draft is required in this process, meaning that the mold has no split lines, leading to the absence of the forming of flash and the reduction or elimination of further finishing processes.
This reduction in post-casting processes reduces the amount of material wasted during the process as well as a reduction in production cost per unit.
Because lost foam casting is such a 'simplistic' process, it is a much more affordable process (within the right production circumstances). When compared to investment casting, this process has fewer manufacturing steps, risers are usually not required, foam is more inexpensive than wax, and, within the right boundaries, it can be a more economically viable casting process.
The foam used in the casting process is easy to manipulate, glue and carve - this allows freedom and flexibility in design. Another advantage offered by foam casting is the fact that it allows the consolidation of parts, in many cases where other casting processes would have required the production of one or more parts followed by down-the-line assembly.
The Disadvantages of Lost Foam Casting
Like all casting processes, foam casting has its disadvantages, the first being the cost of the pattern needed to cast the part. These pattern costs can be high in low volume production cycles. In cases where a die is used to create a pattern, the initial cost for pattern production can also be high.
Tooling used in this process is also highly specialized, typically making use of a split-cavity machined aluminum die which is a negative mold from which the foam pattern is made. Requiring experienced tooling manufacturers and costing a considerable amount of project funds, the positive side of these tools is that it can have between three and four times the life cycle when compared to the tools used in permanent mold casting and die casting processes.
Patterns are also easily damaged and distorted as it is made of low strength materials. A very good process control is also needed in this casting method as a scrapped casting will mean the replacement of not only the mold, but the pattern used to produce it as well.
In general, manufacturing lost foamed parts are more expensive than other casting processes, but the following advantages in some cases are able to take precedent over these costs:
- Tighter tolerances can be casted using the lost foam casting process
- A reduction of weight in parts are possible when using lost foam casting
- The as-cast features of lost foamed parts reduces or eliminates further machining and part clean-up.
- Casts that require drilling, milling, turning and grinding can be produced by this process using only 0.020" to 0.030" of machine stock.
If you would like to learn more about the lost foam casting process, please feel free to visit our How Lost Foam Casting Works page. You can find more information on the defects of lost foam parts on our Problems of Surface Carbon in Lost Foam Cast Parts page.
Further Suggested Reading:
- How Lost Foam Casting Works
- Lost Foam Casting Tolerances
- Metals that can be Lost Foamed
- Problems of Surface Carbon in Lost Foam Cast Parts
- Surface Finish for Lost Foam Cast Parts