Additive manufacturing would be used to form molds to be used for amorphous alloys, or “bulk metallic glass”
In March, Apple Inc. was granted a patent for a 3D printing process to be used to form investment-casting molds, which would be used to form parts from amorphous alloys. The two-layer mold would be used for a hollow casting process, solidifying molten metal in the cavity between the two layers.
The abstract for U.S. Patent No. 20160067766A1 reads:
“Described herein is a method of forming a 3D investment mold using a layer-by-layer construction (3D printing). The mold is configured for receipt of a molten alloy having a composition configured to form a bulk metallic glass (BMG) on cooling. The mold has a hollow interior between inner and outer walls. The hollow interior receives the molten alloy for molding it between the inner and outer walls of the mold. A method of casting using the 3D investment mold is also disclosed, which may include filling the mold with molten alloy, removing bubbles, quenching the molten alloy in the mold, and then removing the mold.”