Gorilla Glass
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.[1]
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.[2] It is manufactured in Harrodsburg, Kentucky; in Asan, South Korea;[3] and in Taiwan. In October 2017, some five billion devices globally contained Gorilla Glass.[4] 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.[5][6][7][4]
Background and development[edit]
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"[8] marketed as Chemcor. The product was used until the early 1990s in commercial and industrial applications, including automotive, aviation and pharmaceutical uses,[8] notably in approximately 100 Dodge Dart and Plymouth Barracuda racing cars in 1968, where minimizing the vehicle's weight was essential.[9]
Experimentation was revived in 2005, investigating whether the glass could be made thin enough for use in consumer electronics.[10] Although not called Gorilla Glass at the time, it was brought into commercial use with the launch of the iPhone in June 2007.[11][12] 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.[13] The scratch-resistant glass that shipped[14] on the first-generation iPhone would eventually come to be known as Gorilla Glass, officially introduced in February 2008.[15] Corning further developed the material for a variety of smartphones and other consumer electronics devices for a range of companies.[16][17][18]
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),[19] which allows the glass to be thin without being fragile. The glass can be recycled.[16]
In December 2015, Ford announced that it would use the material for the windshield and rear window of its second-generation Ford GT sports car going on sale in 2016.[20] It later spread to mainstream models such as the Ford F-150 and Jeep Wrangler.[21]
Manufacture[edit]
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 400 °C (750 °F),[22] 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,[23] and overall crack-resistance,[24] making it resistant to damage from everyday use.[22]
Related products[edit]
On October 26, 2011, Corning announced the commercial launch of Lotus Glass, designed for OLED and next-generation LC displays.[69] The intrinsic thermal consistency of Lotus Glass allows it to retain its shape and quality during high-temperature processing. Decreased compaction and variation during the crystallization and activation step further reduce stress and distortions to the substrate. This enables tighter design rules in advanced backplanes for higher resolution and faster response time.[70] According to Corning, Gorilla Glass is specifically a cover glass for the exterior of display devices while Lotus Glass is designed as a glass substrate to be used within liquid crystal display panels. In other words, a single product could incorporate both Gorilla Glass and Lotus Glass.[71]
On February 2, 2012, Corning Incorporated and Samsung Mobile Display Co., Ltd. signed an agreement to establish a new equity venture for the manufacture of specialty glass substrates for the OLED device market in Korea. The joint venture is based on Lotus Glass.[72] Lotus XT Glass became available in 2013.[73]
In 2012, Corning introduced Willow Glass,[74] a flexible glass based on borosilicate glass,[75] launched for use as a display substrate.
Ceramic Shield, a ceramic-hardened front glass, was co-developed with Apple and is used on all iPhones from iPhone 12 onwards (except the third-generation iPhone SE).[76]
Ceverit, a 1970s chemically hardened glass also known as Superfest and CV-Glas
