Ultra-hard sapphire glass for smartphones

Glass Gorilla Glass does not match the characteristics of artificial sapphire - a transparent crystalline form of alumina (Al ₂ O ₃ ). Sapphire has a hardness of 9 on the Mohs scale, second only to diamond in natural materials. Accordingly, it is scratched only with diamond and substances of similar hardness.

High strength glass Gorilla Glass of aluminosilicate was obtained in 1962 and has been used in industry since 2008. At the same time, an order of magnitude more expensive transparent sapphire is now used as raw material for the manufacture of ophthalmic scalpels, eye lenses, portholes in space stations, protective glasses on rocket optics and airplanes, as well as protective glass on expensive wrist watches and in some other products. . In the iPhone 5, a sapphire glass protects the camera lens.


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Like Gorilla Glass, artificial sapphires were not used everywhere in consumer electronics just because of their high cost. If now a sheet of Gorilla Glass costs about $ 3, then a similar sapphire sheet costs about $ 30. But in recent years, the production of artificial sapphires has increased dramatically. To obtain artificial sapphire, you need to melt Al ₂ O ₃ , after which the material slowly cools in special conditions, forming a sapphire crystal. After Russia and the USA, this technology was mastered in China, Japan, South Korea, Ukraine, Belarus and some other countries, so prices are falling very quickly. According to analysts, in a couple of years the cost will drop to $ 20, and the first model of a smartphone with sapphire crystal or a thin sapphire coating may appear as early as 2013.

The American company GT Advanced Technologies recently announced the development of a new method of applying ultra-thin sapphire coating. The technology was originally developed for the manufacture of solar photovoltaic films and was acquired from another company Twin Creeks Technologies. If this method is brought to the stage of commercial production, the cost of "sapphire screens" will be halved.