Gorilla Glass is a brand of chemically strengthened glass developed and manufactured by Corning. It is in its eighth generation. Designed to be thin, light and damage-resistant, the glass gains its surface strength, ability to contain flaws, and crack-resistance by being immersed in a hot, potassium-salt, ion-exchange bath.
The alkali-aluminosilicate sheet glass is used primarily as cover glass for portable electronic devices, including mobile phones, smartwatches, portable media players, portable computer displays, and television screens. It is manufactured in Harrodsburg, Kentucky; in Asan, South Korea; and in Taiwan. In October 2017, some five billion devices globally contained Gorilla Glass. While dominating its market, Gorilla Glass faces varying competition from close equivalents, including AGC Inc.'s Dragontrail and Schott AG's Xensation and synthetic sapphire.
Background and development
Corning experimented with chemically strengthened glass in 1960 as part of a "Project Muscle" initiative. Within a few years they had developed a "muscled glass" marketed as Chemcor. The product was used until the early 1990s in commercial and industrial applications, including automotive, aviation and pharmaceutical uses, notably in approximately 100 Dodge Dart and Plymouth Barracuda racing cars in 1968, where minimizing the vehicle's weight was essential.
Experimentation was revived in 2005, investigating whether the glass could be made thin enough for use in consumer electronics. Although not called Gorilla Glass at the time, it was brought into commercial use with the launch of the new iPhone in June 2007. The iPhone that Steve Jobs revealed in January 2007 still featured a plastic display. The day after he held up the plastic iPhone on stage, Jobs complained about scratches that had developed on the phone's display after carrying it around in his pocket. Apple then contacted Corning and asked for a thin, toughened glass to be used in its new phone. The scratch-resistant glass that shipped on the first-generation iPhone would eventually come to be known as Gorilla Glass, officially introduced in February 2008. Corning further developed the material for a variety of smartphones and other consumer electronics devices for a range of companies.
Corning markets the material's primary properties as its high scratch-resistance (protective coating) and its hardness (with a Vickers hardness test rating of 622 to 701), which allows the glass to be thin without being fragile. The glass can be recycled.
In December 2015, Ford announced that it would use the material for a windshield and rear window on its Ford GT sports car beginning in 2016; it later spread to mainstream models such as the Ford F-150 and Jeep Wrangler.
Manufacture
During its manufacture, the glass is toughened by ion exchange. The material is immersed in a molten alkaline potassium salt at a temperature of approximately , wherein smaller sodium ions in the glass are replaced by larger potassium ions from the salt bath. The larger ions occupy more volume and thereby create a surface layer of high residual compressive stress, giving the glass surface increased strength, the ability to contain flaws, and overall crack-resistance, making it resistant to damage from everyday use.
Generations
The first generation of Gorilla Glass was introduced in February 2008. By 2010, the glass had been used in approximately 20% of mobile handsets worldwide, about 200 million units.
The second generation, called "Gorilla Glass 2", was introduced in January 2012. It is 20% thinner than the original Gorilla Glass. In October 2012, Corning announced that over one billion mobile devices used Gorilla Glass.
Gorilla Glass 3 was introduced at CES 2013 on January 7. According to Corning, the material is up to three times more scratch-resistant than the previous version, with enhanced ability to resist deep scratches that typically weaken glass. Promotional material for Gorilla Glass 3 claims that it is 40% more scratch-resistant in addition to being more flexible. The design of Gorilla Glass 3 was Corning's first use of atomic-scale modeling before the material was melted in laboratories, with the prediction of the optimal composition obtained through the application of rigidity theory. The first phone to use Gorilla Glass 3 was the Samsung Galaxy S4.