Everything You Need to Know About Investment Casting & Electromagnetic Pumps
While many casting processes are capable of producing high-quality, dimensionally perfect parts, few are capable of matching the precision of investment casting. The method creates highly accurate parts with superior surface quality – and excels at casting parts with complex geometries and designs. The aerospace, automotive and medical device industries are among those that rely on investment casting to create some of their most intricate parts.
There is a prevalent belief among casters that electromagnetic (EM) pumps are incompatible with the investment casting process – this is a misconception. To set the record straight, here are answers to the most frequently asked questions we hear about EM pumps and investment casting.
Can EM Pumps Be Used in Investment Casting?
Yes. While EM pumps may not be a suitable solution for every investment casting application, the notion that the pumps and process can’t mix is misconceived. EM pumps can work in harmony with an investment casting process. In fact, EM pumps solve many of the most common problems investment casters face.
What are the Benefits of Using an EM Pump in an Investment Casting Process?
Investment casting is, for most foundries, a very manual process. Typically, molten metal is hand ladled from furnace to casting – which can create safety, labor and metal quality issues. EM pumps, a form of casting automation that uses magnetism – and no moving parts – to move molten metal, are a salve to all three of these issues. EM pumps:
- Increase safety: EM pumps move workers away from molten metal, which greatly reduces the risk of spills and burns and saves employees from overheating or overexerting themselves
- Reduce labor demands: by automating one of the most labor-intensive parts of the investment casting process, EM pumps allow foundries to repurpose employees to other parts of the foundry – and reduce the labor churn that results when foundry work is demanding and unsafe
- Improve metal quality and consistency: when metal is hand ladled (or poured using an automated or robotic ladle), dross can make its way into the casting and defect-causing turbulent flow results; EM pumps pull clean, dross-free metal from deep below the furnace’s surface, and reduce – or even eliminate – turbulence, which minimizes the risk of bubbles, porosity and other defects
Are EM Pumps an Appropriate Fit for Every Investment Casting Application?
While EM pumps alleviate safety and labor concerns – and improve the quality of metal – they are not an appropriate fit for all investment casting applications. EM pumps perform their best in full furnaces that are continuously charged with metal. Therefore, they are not an appropriate fit for investment casting applications with:
- Extremely limited runs: foundries that slowly produce a limited number of parts generally don’t require the volume of molten metal EM pumps require to properly function
- Frequent alloy changeovers: batch melting is common in investment casting foundries; if changeovers occur very frequently, furnaces likely don’t maintain a high enough volume of a single metal for EM pumps to function
EM pumps are also not compatible with all furnace types – regardless of the casting process used. Both of the EM pumps CMI Novacast manufactures for aluminum foundries (the PG 300 and PG 450) are incompatible with:
- Induction furnaces: which cause EM pumps to malfunction because they operate off the same principal
- Crucible furnaces under 2,000 lbs.: which aren’t spacious enough to fit the EM pump inside and maintain the metal level needed for the pump to work properly
Which Investment Casting Applications Most Benefit from EM Pumps?
Investment casters that manufacture a high volume of parts using a single alloy – and seek to reduce labor demands and increase safety – most benefit from EM pumps.
EM pumps can be used in a variety of furnaces – so long as their bath is spacious enough. Reverberatory furnaces and stack melters are an ideal fit for both the PG 300 and PG 450, but certain crucible furnaces (over 2,000 lbs.) and modified pressure furnaces can also be used if they are large enough to fit the pump and maintain a high volume of metal.
Is an EM Pump Right for Your Foundry?
If you are investment caster and still aren’t sure whether an EM pump is right for your foundry, contact a CMI Novacast factory expert to learn more.
Since its founding in 1981, CMI Novacast has supplied foundries with EM pumps and related systems, including heated launders, preheat ovens and control systems, to automate casting and alleviate common casting problems.
