While there are various casting techniques available, for light-metal casting there are two methods that represent the bulk of overall casting numbers. High pressure die casting is used in approx. 50% of overall light metal casting, while low pressure die casting is used in about 20%.

New Century Heaters has engineered our immersion heaters specifically for molten metal. For more information our Immersion Heaters, contact us.

Which Method Should You Choose?

There are several considerations in determining the best casting method for a given application, but first, a brief explanation of the two methods is beneficial.

In a high pressure die casting application, molten metal is forced (injected) horizontally into the die. One half of the die isHigh Low Pressure Die Casting attached to a stationary machine plate while the other half is attached to a movable plate. As pressures of up to 1,200 bar are achieved during pouring, the bolts holding the two die halves together must have sufficient locking force. After the casted pieces have solidified and cooled, the die can then be opened, with the casting removed from the die by ejector pins.

With a low pressure die casting system, the two die halves are arranged like a high-pressure application (one on a moveable plate and the other stationary), but now the machine is aligned vertically. The furnace holding the molten metal is instead located beneath the fixed die plate. The pressure used in a low-pressure application is 1 bar or less, which pushes the molten metal through an intake port into the die chamber against gravity. After the die is filled this pressure is maintained during metal cooling which enables additional metal to continue flowing that will counter volume deficits that may occur as the metal solidifies.

High vs. Low Pressure Advantages/Disadvantages

High-Pressure Die Casting Advantages:

  • Shorter casting cycles
  • Die-casted part wall thicknesses down to 0.40 mm depending on application
  • Smoother finishes of die-casted parts, finishes can be applied directly to casted parts.
  • Higher material utilization, and no “feeders” are required
  • Better-suited for automation

Disadvantages:

  • Die creation is more expensive and complicated
  • Die-casted part strength is lower (rapid metal cooling rate can concentrate porosity due to trapped air, as well as inclusions being present at the centerline of the castings
  • Very large parts are generally not available due to die-cast weight being limited by required machine locking force.
  • Higher operational costs due to the more expensive machine and dies, makes this method typically used only in high-volume part production.

Low-Pressure Die Casting Advantages:

  • Superior strength values of parts
  • No requirement for complicated machinery and die technology
  • Parts up to approx 150 kg can be casted
  • Higher dimensional accuracy of parts
  • Higher material utilization, and no “feeders” are required
  • Well-suited for complex geometry part designs
  • Less expensive overall option

Disadvantages:

  • Longer casting cycles (perhaps offset as cheaper technology, and easily lent to automation).
  • Wall thickness of die-casted parts is 3mm

Contact NCH for our full immersion heater catalog, based on your specific requirements and application we will work with you to find the optimal solution.

 

 

 

Immersion Heating System Details

New Century Heaters has engineered our immersion heaters specifically for molten metal. These heaters coupled with specially designed protection tubes provide the most robust and efficient molten metal heat source in the industry.

Our immersion heating elements are made of heavy gage ICA wire on cast ceramic cores that guarantee wire spacing to evenly distribute the heat through high density, high conductivity, non-wetting protection tubes.

We use the heaviest gage wire in the industry to provide robust, long-lived heaters that can be operated up to 2,000 degrees Fahrenheit. The wire is recessed in separating groves that are precision cast in a ceramic core that is engineered to compliment the mating protection tube. Because of this, the coils can never touch each other and short out. Extra heavy leads are brought out and insulated away from the heater core to provide trouble free connections.

If you are a manufacturer of furnace, we want to talk to you.  Contact us today for a free, quick estimate!

If you are looking to replace your immersion heater found in a melting furnace,  contact us!