Implementation of Metal Casting Best Practices - EERE - U.S. ...

1. Implemented Best Practices
Molten Metal Handling
Die Casting Plant-2 has an outstanding melt/metal handling system. As mentioned above, the
plant receives its molten metal supply from its smelter twice a day. Delivered metal is held in a
large reverberatory furnace from which it is transferred to a launder system that distributes it to
the die casting machines. The metal goes through a filtration process prior to entering the
covered launder system, thus reducing the amount of dross that goes through the system. The
launder system keeps the molten metal at an optimal temperature and minimizes fluctuations in
temperature when pouring which, if not controlled, can lead to high scrap rates and wasted
processing energy.
The plant fluxes molten alloys to minimize the melt loss. It currently experiences a 2% melt loss,
which is much lower than the industry average. The plant has also implemented a program to
separate dross from metallics, saving $28,000 annually by receiving the optimal buy-back price
for its dross and reducing the energy consumed in processing good metallic material with the
dross.
They further reduce process inefficiencies by using computer monitoring of the molten metal
handling throughout the operation, thereby enabling the plant to identify and correct problems as
soon as they occur in the system. This optimal handling not only limits the amount of scrap
produced at the plant from variations in pouring temperatures, but also provides for a safer
working environment by reducing the number of employees that actually handle the molten alloy.
Simulation Modeling
Currently, the design facility at corporate headquarters provides complete tooling services for the
plant. The facility runs simulation software on all new dies. These simulations primarily involve
flow modeling, although the plant is beginning to run thermal models as well. The facility uses a
variety of modeling software including CastView, Finite Element, Magma, and EKK.
The plant will occasionally run simulations if a new design poses a problem after it arrives at the
plant. This allows the plant to troubleshoot the design of the die or the configurations of the gates
and risers. Plant personnel employ the Magma software to perform this task as they find it to be
the most accurate tool.
The modeling of all new dies and products has benefited both the plant and the corporation. The
current internal scrap rate at the plant on new work is running at 2-3%, which is lower than the
industry average of 4-5%. 49 This provides an obvious competitive advantage to the plant, since
less time and effort spent controlling scrap translate directly into cost and energy savings.
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