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Sapphire Glass Didn't Pass iPhone Drop Test According to Reports
SternisheFan notes reports about why Apple didn't use sapphire glass screens in the latest iPhones as many expected. Sapphire screens were part of the iPhone 6 design until the glass repeatedly cracked during standard drop tests conducted by Apple suppliers. So Apple abandoned its sapphire plans before the iPhone 6 product launch September 9. VentureBeat has learned that recent supplier channel checks by an IDC analyst yielded several reports of the sapphire failures and Apple's decision against using the glass material. As we heard on Tuesday in Cupertino, both the iPhone 6 and the larger iPhone 6 Plus will ship with screens made of "ion-strengthened" glass. This was apparently Apple's second choice. IDC analyst Danielle Levitas says it isn't clear when exactly the drop-test failures took place, or when Apple abandoned plans for sapphire-screened iPhones. She says the poor drop-test results, combined with the relative high cost of sapphire glass, could have made plans to ship sapphire glass phones too risky. One researcher who covers GT Advanced Technologies, the company that was to produce the glass for the iPhone 6, wrote in a research note earlier this week that plans for the sapphire screens were cancelled in August, just weeks before the September 9 launch. The new Apple Watches (except the "Sport" version) do use sapphire for their screens. Levitas believes that the glass for the smaller 1.5-inch and 1.7-inch watch screens was less likely to break in drop tests.
..might simply have been not appreciably better than glass alternatives.
if true (this sounds like speculation) kudos apple for not releasing something just because they could.
Isn't that what standard hardened glass is?
Apple is creating its own supply chain devoted to producing and finishing synthetic sapphire crystal in unprecedented quantities. The new Mesa, Ariz., plant, in a partnership with sapphire furnace maker GT Advanced Technologies (GTAT) of Merrimack, N.H., will make Apple one of the world’s largest sapphire producers when it reaches full capacity, probably in late 2014. By doing so, Apple is assured of a very large amount of sapphire and insulates itself from the ups and downs of sapphire material pricing in the global market.
In keeping with long-standing practice, Apple has never publicly discussed the Arizona project or what it intends to do with such a vast amount of sapphire material. Rumors and more or less informed speculation have flourished in that silence.
The Arizona project was revealed in November, with Apple paying $578 million for GTAT to install and run its advanced sapphire growth furnaces in a plant built and owned by Apple. The news triggered a frenzy of speculation that Apple planned to use sapphire crystal sheets to replace the glass currently used in touch displays for its 2014 iPhones, iPads or a new line of “wearables” such as the long-rumored iWatch, or all of the above.
That’s only the tip of Apple’s investment. Once the 253-pound “hockey puck” shaped sapphire boules emerge from the furnaces, they’ll be shipped to Apple’s supply chain partners in Asia, including Biel Crystal Manufactory and Lens One Technology Co., for slicing, polishing, laser cutting, coating and eventual assembly.
But to do all this, these companies, and Apple, will have to invest heavily in new equipment that can handle sapphire, since only diamond is harder, and handle it in the quantities that Apple will produce. That’s not a simple process.
Natural sapphire is a gemstone variety of the mineral corundum, a crystalline form of aluminum oxide. Corundum is colorless, but in natural sapphires, various impurities create a range of colors: chromium makes the gem red, becoming a ruby; iron and titanium create the prized cornflower blue of a true sapphire.
Synthetic sapphire is colorless, unless deliberately colored. GTAT’s ASF uses a variation of what’s called the Czochralski process, combining the melting of aluminum oxide, a seed sapphire crystal, and heat extraction to crystalize the alumina melt. [For more details, see the accompanying slideshow: “Why Apple’s sapphire plan is as hard as the mineral itself”] Like natural sapphire, the synthetic is incredibly hard and that hardness creates challenges for using it.
“When the [sapphire] area is larger, with the increased hardness, it takes more aggressive abrasives to grind and polish it,” says Jennifer Stone-Sunderberg, who has a Ph.D. in solid state chemistry and crystal growth, and now consults in this field as a managing director of Crystal Solutions of Portland, Ore. “It’s time-consuming to polish something that hard.”
Secondly, it means overcoming a surprising problem: despite its hardness, synthetic sapphire can be prone to fracturing, at almost any point in this finishing process, due to impurities or to the presence of unresolved strains in the crystalline structure.
“That’s something that’s being very carefully measured and tested,” says Stone-Sunderberg. “Fracturing is probably of the highest concern. If a product is released with a more expensive touch screen [cover] and consumers experience fracturing, they’re going to be highly disappointed. It would be devastating to the sapphire industry.”
Tackling these issues on this scale and schedule has never been attempted before.
“GTAT and the rest of the Apple supply chain involved in this new sapphire component indeed have to execute an unprecedented - for the sapphire industry - r
One of the largest uses for artificial sapphire is supermarket barcode scanners. No one's putting it there because they feel a need to bling-out the supermarket. It's there because any surface that has stuff dragged across it all day, every day either needs to be incredible scratch-resistant or replaced way too often.
The glass consists of a thin sheet of alkali-aluminosilicate. Gorilla Glass is strengthened using an ion-exchange process which forces large ions into the spaces between molecules on the glass surface. Specifically, glass is placed in a 400C molten potassium salt bath, which forces potassium ions to replace the sodium ions originally in the glass. The larger potassium ions take up more space between the other atoms in the glass. As the glass cools, the crunched-together atoms produce a high level of compressive stress in the glass that helps protect the surface from mechanical damage.
http://chemistry.about.com/od/...
How Sapphire Glass is made...
http://www.businessinsider.com...
Actually it's not. Moissanite (silicon carbide) is harder. 9.5 on the Mohs scale, vs 9 for sapphire/corundum, 10 for diamond. Its structure is the same as diamond, except it alternates between silicon and carbon atoms, the silicon-carbon bond being nearly as strong as a carbon-carbon bond. I first ran across it (as an opaque conglomerate of smaller crystals) as guides for fishing rods - the hardness prevents braided lines from gouging a groove in the guide. There are a bunch of other materials harder than corundum, but I believe moissanite is the only transparent one.
Remember what your momma taught you - never trust a salesman.
Back in the 1920s-1940s as cars became more popular, more people started dying in car crashes. In response, the auto manufacturers did the obvious thing and started making the cars stronger and stronger. And people kept dying.
It wasn't until the 1950s when the first controlled crash tests were done, that they discovered that the stronger car bodies were the worst possible thing you could do. They did nothing to reduce the kinetic energy of the occupants before impact. The car would hit, the strong body would stop moving almost instantly, and the occupants would keep flying forward at full speed until they hit the front of the car. This is what led to the crumple zones we have today - where the car body deliberately flexes and deforms to absorb crash energy, lessening the impact forces on the occupants.
I think phones are going to go the same way. Rather than build the bodies and faces stronger and stronger to try to make them survive drops, they're going to be replaced with flexible screens once those come down in price and become commonplace. Bend and flex to absorb the impact energy, not try to stiffly resist it until something shatters. Scratches can be handled by a disposable plastic protector (I go through about one a year, so it's not at all inconvenient).