The fascinating science of Gorilla Glass

The fascinating science of Gorilla Glass

Summary: A new article explores how Corning reinvented itself from a fiberglass company into one that creates millions of square feet of ultra-thin, ultra-strong glass found in everything from the Galaxy S3 to the Lumia 900 to the iPhone.

TOPICS: Apple, iPhone
The fascinating science of Gorilla Glass - Jason O'Grady

Bryan Gardiner wrote an amazing article for Wired that explores the creation and history of Gorilla Glass. Glass Works: How Corning Created the Ultrathin, Ultrastrong is an excellent read, especially if you own an iPhone.

The ubiquitous glass -- found in the iPhone, Galaxy S3 and Lumia 900 -- was born out of an R&D project at Corning that looked for ways to leverage its experience in making strengthened glass. The breakthrough occured when Corning discovered that adding aluminum oxide to its glass composition before bathing it in hot potassium salt created glass with unmatched strength.

Gorilla Glass 1.0 is able to withstand 100,000 pounds of pressure per square inch wheras normal glass can handle about 7,000 PSI. A 1-mm-thick piece of today's Gorilla Glass 2.0 (believed to be what's included in the iPhone 5) can withstand 2 joules of energy from an impact hammer without shattering.

Here are some other interesting nuggets from the article:


Before there was Gorilla Glass, there as Corningware - Jason O'Grady

Corning's first synthetic glass-ceramic, dubbed Pyroceram, is lighter than aluminum, harder than high-carbon steel, and many times stronger than regular soda-lime glass. Pyroceram eventually found its way into everything from missile nose cones to chemistry labs. It could also be used in microwave ovens, and in 1959 Pyroceram debuted as a line of space-age serving dishes called Corningware.

Gorilla Glass - not so good for car windshields - Jason O'Grady

In 1962 Corning marketed its new glass to manufacturers of phone booths, prison windows, and eyeglasses as Chemcor, but it was recalled for fear of the potentially explosive breaks. Chemcor seemed liked a good fit for car windshield (it briefly appeared in some AMC Javelins) but the added cost was a deal breaker for auto manufacturers. It didn’t help that crash tests found that "head deceleration was significantly higher" on Chemcor windshields, meaning that windshields would remain intact, but skulls would not. The product, known internally as "0317," was put onto a shelf in 1971 until a more practical application could be found. 

Soda lime glass compared to Gorilla Glass - Jason O'Grady

In 2005 Corning revisited its 4mm thick Chemcor samples when Motorola released the Razr V3 flip phone. Instead of high-impact plastic, the V3 featured a glass screen which set the wheels in motion. Corning revived "0317 and the project was codenamed "Gorilla Glass." In February 2007 Steve Jobs asked Corning CEO Wendell Weeks if he could create millions of square feet of 1.3mm thin, ultrastrong glass in six months

The problems were numerous. Chemcor had never been mass-produced on that type of scale and it wasn't known if it could be made ultrathin and still retain its strength. Suffice it to say that the little company from Harrodsburg Kentucky had a huge hit on its hands. Corning’s Gorilla Glass revenue skyrocketed from $20 million in 2007 to $700 million in 2011 and it plans on releasing an even stronger version 3.0 "early next year."

The article is an excellent read, and highly recommended.

Topics: Apple, iPhone

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  • And it still shatters on impact.

    And it still shatters on impact. It's respectably stronger, yes, but if you hit it right, you'll still break it. I still have to get something like the Otterbox to protect the phone.
    • I think anything with a crystalline structure...

      will shatter if hit in the right (or wrong) place.
    • It is still a kind of glass.

      The problem with glass is that it is very very hard but not flexible at all. Once you exceed it's impact tolerance it WILL shatter. This is due to it's crystalline molecular structure. The big advantage here is that the stronger the glass the more resistant it is to scratches.
      Plastic on the other hand isn't very hard at all most of the time but very flexible. It is made up of long chains that can bend and interact with each other. The obvious drawback is that it gets scratched easily which can be seen on the screens of old phones.
      Personally I prefer a screen that doesn't get scratches easily. And until we figure out how to make Star Trek-like see-through metals that are thicker than just a couple layers of atoms Gorilla Glass seems to be our best alternative.
      Oh and by the way, most clear plastics that are very hard are usually also very brittle and shatter easily as well. My model building experience tells me that. So hard clear plastics aren't a good alternative as well :P
      • But glass isn't crystalline

        Glass is an amorphous (non-crystalline) solid material. It's essentially a very, very thick liquid. I liken it to the road tar I played with as a child. When it was warm, it was flexible. Some of us kids even chewed it like chewing gum! However, if we put it in the freezer, it would shatter like glass when we hit it with a hammer.
        • Yes it is

          This "glass is just a slow liquid" thing is a common misconception from people who claim that very old glass panes are thicker at the bottom than at the top. They gennerally are, but that's beacuse old glass dosen't have the quality of manufacturing avaliable to us today. So old glass panes were installed with the thicker part at the bottom to better stand up to the compressive stresses, not beacsue the completley solid glass somehow flowed under gravity.
          John Gates
  • i love reading things like this

    Random facts and info are very interesting.
  • Hmmm.

    Aluminum Oxide? Sounds like Mr. Scott's transparent aluminum that he needed to take transport the whale.
    • Transparent Aluminum?

      I was thinking the same thing.

      "Isn't that quaint"
    • Transparent

      We already have a lot of experience with transparent aluminum oxide. We call it sapphire.
  • That's good to know.

    Glass is awesome, it's translucent, it's hard to beat that.

    Also, Steve Jobs looked to an American company that didn't have the capability to scale (at the time) to do this work. That should be noted for the Apple hating legions.
    Mahstehr Blahstehr
  • Owens Corning is the fiberglass company, not Corning

    Corning was one of the original partners in Owens Corning, but Owens Corning was spun off from Corning in the 1930s. Among Corning's claims-to-fame are: Pyrex(R) labware (the Pyrex(R) kitchenware line was recently sold and is no longer made of borosilicate glass) and the 200-inch mirror for the Hale telescope at Mt. Palomar observatory (there is a duplicate on display at the Corning museum in Corning, NY).
    Mister Bear