Two patents recently published by the US Patent and Trademark Office (USPTO) suggest Apple is still working on developing production processes for Liquidmetal
. The two patents describe methods for casting bulk metallic glass (BMG) in different ways, including allowing multiple BMGs to surround other alloys, as well as techniques to melt BMG feedstock using horizontal cold crucible induction melting (CCIM) systems.
Patent 9,103,009, the casting patent
, is said by AppleInsider
to solve an issue where crystals can form during the cooling process, typically when it is cast inside a metal or ceramic mold in bulk, slowly cooled, or using impurities in the raw material. If crystals form, this typically negates any benefits the material has, such as strength, and is usually rejected from the production process.
Diagram showing layering of Liquidmetal, other alloys in casting patent
Apple proposes in the patent that there could be three different casting techniques that can combine BMGs such as Liquidmetal with other metal alloys in order to combine the material properties in the same component. In the case of using the BMG core with a metal shell, a metal core with a BMG shell, and a BMG/metal alloyed item, Apple's method requires complete control over the heating and cooling of materials, in order to retain the alloy properties it requires.
The other patent
, number 9,101,977, proposes the changing of technique when melting via an induction coil, using a horizontal instead of vertical technique. In doing this, Apple can not only perform material filtering more easily, but it also allows for the use of a copper crucible, which helps minimize material contamination.
Diagram showing horizontal CCIM process
It is unclear if Apple is actively using the techniques described in the patents, but considering it holds the exclusive rights
to Liquidmetal technology until 2016, it is the prime candidate to do so. It is possible Apple could use both patents to ramp up its use of Liquidmetal in its products, though it is unlikely it will create entire devices using the material for quite some time.