Why Magnesium Injected Metal Molding?
How Metal Molding Works
Magnesium metal molding is a high-speed, semi-solid process that utilizes plastic injection molding methodology, thereby eliminating the environmental impacts typical of die-casting (i.e. SF6 and SO2).
Unlike die-casting, the metal molding process does not require the handling of molten metals in separate melting and transfer systems. The entire process takes place in a closed machine which can be monitored and controlled by one person.
Chips of magnesium alloy are fed at room temperature into the hopper of a molding machine under a blanket of argon gas.
The magnesium chips are electrically heated in the barrel of the machine to about 1076°F (580°C) to 1112°F (600°C). This solid-to-liquid phase is tightly controlled, with the magnesium converted into a uniform, semi-solid slurry that has a low, yet stable viscosity.
Once the predetermined viscosity and shot size have been achieved, the material is injected at high-speed into the die cavity. Current machine sizes range up to 1,000 metric tons of clamp capacity.
After molding, a robotics arm removes the component from the die and moves it onto a conveyer belt where it is trimmed, boxed, and prepared for shipping.
Magnesium metal molding can produce zero-draft parts that hold dimensional tolerances better than typical die casting methods, and improve surface finishes if required.
View why magnesium has become a major player in component design and manufacture.
View the properties of injection molded magnesium alloys versus other magnesium alloys. (PDF)