Amorphous Metal Alloys

Apple has concluded an exclusive agreement on the use of amorphous metal alloys with a unique atomic structure, which allows products to be more durable, lightweight, and also more resistant to wear and corrosion.



***

Amorphous metal alloys were developed by a group of researchers from the California Institute of Technology in 1960. (Duvez, Willens and Clement). A method was obtained for quenching the melt in an amorphous state in metal alloys. However, widespread acceptance of amorphous metallic materials in science and technology began in the early 1970s, when highly efficient methods were developed for their production in the form of thin tape or wire. It became clear that the concept of a “metallic body” can no longer be regarded as a synonym for the concept of a “crystalline body”, that with the production of a metallic substance in a new amorphous state, it is necessary to consider two essentially different in their nature and properties class of metallic bodies - crystalline and amorphous.
')
For the first time for commercial purposes, the product was used in 2003 to create US Department of Defense equipment, medical equipment, and even to create sporting goods, such as tennis rackets and golf clubs.

Apple acquired the rights to use alloys for commercial purposes, but in all other areas that Apple does not deal with, Liquidmetal reserved the rights to the technology.
The agreement was concluded on August 5th. It was signed by Larry Buffington, who is the president and CEO of Liquidmetal Technologies.

Atomic structure of Liquidmetal (liquid metals):



Crystal Amorphous Structure
lattice

In ordinary metals, the structure is a crystal lattice . Liquidmetal alloys have an “amorphous” atomic structure, that is, they do not exhibit different properties in different directions and do not have a specific melting point. The properties of Liquidmetal are superior to those of ordinary metals.

From the Liquidmetal property:
· High hardness
· High hardness to weight ratio
· Superior elastic limit
· High corrosion resistance
· High wear resistance
· Unique acoustic properties

One of the results of the unique atomic structure of Liquidmetal alloys is high fluidity, which approaches the theoretical limit and is much higher than in crystalline metals and alloys. For example, the yield strength of more than 250 KSI was achieved in the Liquidmetal Zr-based alloys (VIT-001 series). This is more than two times greater than in conventional titanium alloys.

Another unique property of Liquidmetal alloys is the highest limit of elasticity, i.e. the ability to retain its original shape after undergoing very high loads and stresses. In addition, Liquidmetal is more resistant to corrosion than their regular lattice counterparts because of the unique structure of the atom.


Possible uses for amorphous metallic materials:

Amorphous metals can be used as materials having a high characteristic of strength and ductility. Already since 1974 It was suggested that the use of amorphous alloys in various designs in combination with plastics and rubbers, as well as for the manufacture of springs and small cutting tools. The main obstacles here were the high cost, poor resistance to heat and not the possibility of obtaining material in a form other than tape. However, recently with the advent of methods of pulling fibers out of a rotating drum, it became possible to obtain round wire (diameter 200 μm) from amorphous iron-based alloys. This was a stimulus for exploring the possibilities of amorphous metals as high-strength materials. The wire from an amorphous alloy surpasses even a steel grand piano wire in the strength. Therefore, this amorphous alloy is very promising for use as high-strength materials.
The desire to miniaturize electronic devices has led to the fact that the linear dimensions of current-carrying tracks, contact pads and other elements of modern integrated circuits do not exceed 0.5-1 microns. At submicron sizes of work items, conditions are created for the mutual penetration of atoms — diffusion at the metal-semiconductor interface. Over time, this process leads to short-circuiting of current-carrying paths and device failure. To prevent diffusion, it is necessary to create a thin barrier layer between the semiconductor and the metal.
So it was shown that amorphous metal alloys have the best barrier properties. Diffusion through amorphous layers is very difficult due to the irregularity of the atomic structure. Amorphous alloys of refractory metals have especially good barrier properties.

Conclusion:

Despite the fact that amorphous metals have unique methods for their preparation and special properties that are not found in crystalline metals. Amorphous metals have their disadvantages:

• not high thermal stability.
• not sufficient stability over time (which reduces their reliability).
• complete weldability (therefore, amorphous metals are not suitable for large-sized structures, the impossibility of their use as high-temperature materials).

PS: In the future, it will be known where Apple is going to use amorphous metal alloys))).


The following resources were used to create the article: appleinsider.com , liquidmetal.com , pereplet.ru
Amorphous Metals / Suzuki K., Khudzimori H., Hashimoto K. - M .: Metallurgy, 1987.