Scientists develop 'unbreakable' glass almost as tough as steel

http://ajw.asahi.com/article/sci_tech/technology/AJ201510290034

by Mz • 11 years ago

158 72 11 years ago

ajw.asahi.com

astrodust• 11 years ago

Sounds like a hybrid between glass and "transparent aluminium".

justinsaccount• 11 years ago

So... Gorilla glass?

edit: yeah...

From: https://en.wikipedia.org/wiki/Gorilla_Glass

Gorilla Glass is a brand of specialized toughened glass developed and manufactured by Corning, now in its fourth generation,[1] designed to be thin, light and damage-resistant. This type of glass is not unique to Corning; similar glasses include Asahi Glass Co. Dragontrail and Schott AG Xensation.[2][3]

The alkali-aluminosilicate sheet glass [snip]

(The link is to asahi.com)

logfromblammo• 11 years ago

Gorilla glass uses a post-solidification hardening step.

The glass described in the article uses a higher aluminum content than any other mass-produced glass, to the point where any contact with a solid surface would produce alumina crystals rather than incorporate the aluminum into the glass structure.

So they levitated a glass bead with a continuous stream of air until it solidified. The bead is very strong, but they have no idea how to work the resulting glass into fibers or sheets.

lovemenot• 11 years ago

> (The link is to asahi.com)

Asahi Glass Co. is a separate company to Asahi Shimbun, the news organisation. AGC has a historical connection to the Mitsubishi group through the founder's family, but really is a wholly independent group of companies.

fredkbloggs• 11 years ago

Aye, that's the ticket, laddie!

DiabloD3• 11 years ago

For those downvoting this, please go watch Star Trek IV: The Voyage Home

Bud• 11 years ago

Upvoted this to counteract the idiots.

stephengillie• 11 years ago

Sapphire crystal [1] is something like transparent aluminum rust. Alumina [2] is too, I think. They might be the same thing, I'm not a chemist.

[1] https://en.wikipedia.org/wiki/Sapphire [2] https://en.wikipedia.org/wiki/Aluminium_oxide

Florin_Andrei• 11 years ago

Sapphire and ruby are both aluminum oxide - i.e. 'alumina' - just with different kinds and amounts of impurities.

Yes, it is technically the stuff you get when you throw aluminum powder over a fire and it lights up and burns brightly. But the crystals you obtain that way are very tiny.

gjmulhol• 11 years ago

Alumina is Al2O3 generally, and usually it is polycrystalline. Sapphire is specifically Al2O3 in a certain (very hard) crystal structure.

vibrolax• 11 years ago

While it's not quite transparent aluminum, transparent aluminum oxide ceramics like ALON are used for ballistic armor on ships, helicopters, and other military vehicles.

https://www.youtube.com/watch?v=RnUszxx2pYc

marcosdumay• 11 years ago

Wait. A big elasticity coefficient is not the same as 'unbreakable'.

Being a mixture of silicates and alumina, I'll be very surprised if this is not fragile. There's nothing about it on the article.

personjerry2• 11 years ago

Glass itself isn't always "fragile" https://en.wikipedia.org/wiki/Prince_Rupert%27s_Drop so perhaps we'll be pleasantly surprised

eric_the_read• 11 years ago

Oh man, I love Prince Rupert's Drop. As usual, Smarter Every Day has a great video on them: https://www.youtube.com/watch?v=xe-f4gokRBs

ashmud• 11 years ago

Is this anything like aerogel?

Sephr• 11 years ago

Aerogels aren't known for their structural strength or elasticity, but for their extreme insulative properties.

Someone1234• 11 years ago

This is cool regardless. But I am interested in cost and weight.

If it is too costly we might only see it used in niche applications (e.g. aircraft windows?). But even then if it weighs more than regular glass it may not even be utilised there.

I'd like to see it used on vehicle front windshields, cracks are a constant pain in the butt, and they can leave the rear window and side windows as regular glass for emergency escape (typically only the front one receives most of the debris). But it really comes back to both weight and cost again.

gohrt• 11 years ago

Your windshield is safety glass, so consideration must be given for the need to dissipate energy when a human head collides with it.

https://en.wikipedia.org/wiki/Windshield#Safety

Trivia: A famous lawsuit about the safety of windshield glass was the _Pane_ vs. Ford case in 1917

Johnny5554• 11 years ago

I don't think that safely fracturing when struck by a human is the safety function referred to in the linked article - once a person hits the windshield, the primary safety mechanisms (seatbelts, airbags, and structural integrity of the car) have already failed, so whatever happens at the windshield will make little difference.

What the article says is that the safety role of a windshield (besides not breaking into dangerous shards of glass) is in being strong enough to maintain the structural integrity of the passenger compartment:

Modern, glued-in windshields contribute to the vehicle's rigidity, but the main force for innovation has historically been the need to prevent injury from sharp glass fragments. Almost all nations now require windshields to stay in one piece even if broken, except if pierced by a strong force. Properly installed automobile windshields are also essential to safety; along with the roof of the car, they provide protection to the vehicle's occupants in the case of a roll-over accident.

Today’s windshields are a safety device just like seat belts and airbags. The installation of the auto glass is done with an automotive grade urethane designed specifically for automobiles. The adhesive creates a molecular bond between the glass and the vehicle. If the adhesive bond fails at any point on the glass it can reduce the effectiveness of the air bag and substantially compromise the structural integrity of the roof.

vlehto5• 11 years ago

Glass has density of ~2,5 kg/liter. It's made of silica, that has density of ~2,6. This has about 50% of Alumina in it with typical density of ~4.

So it's likely it would be around 3,3. More than aluminum, less than titanium.

But it's supposedly about ~20 times more rigid than regular glass. For rigidity limited structure, you could make it so much thinner that you get significant weight savings. This could be important for glass fiber structures. Fiber vs. fiber, glass has been able to compete in strength with carbon fiber, but lack of rigidity is the downside. Increase of stiffness might allow for usage of stiffer "matrix" (glue that holds the fibers together). That should increase overall strength. This limitation exists because if matrix is stiffer than the fibers, the structure will rip itself apart under load.

For strength or hardness limited designs, impossible to say. The article says nothing about it. Alumina is one of the hardest substances around, but I would not make any assumptions based on that. Typically it's more about structure than the molecules involved.

For creep and fatigue resistant designs, bulk glasses are pretty useless because of their amorphous structure. Fibers can be used in fatigue situation though. Again the increase in stiffness and the possible increase of matrix stiffness could improve the situation. But the real thing here is how well the matrix can bind to the fibers. That again is impossible to tell.

Windshields? It's big trade off really. Soft amorphic materials scratch easily. (By definition "hardness" is resistance to identation. Just add movement and you have scratching.) Typically "hard" amorphic materials suffer from cracking. This is because hardness usually comes with decreased ductility. But fracture toughness is function of stiffness and ductility. So this material could(?!?) improve hardness while being about as easy cracking as old windshiels. This would be good idea as windshield is mostly mode of fracture limited design. (It matters more how your windshield breaks, than how much energy it takes to break it.)

craigds• 11 years ago

To nitpick, the article uses the words 'tough', 'hard' and 'rigid' to describe this glass, though those all mean different things.

I'd suggest that all glass is both hard and rigid, so presumably 'tough' is what they're going for. If so, the glass should be able to withstand a large tensile force without fracture or permanent deformation.

'unbreakable' is also a little disingenuous. Everything is breakable, given a big enough hammer ;)

such_a_casual2• 11 years ago

They provided technical terminology when they explained that its Young's modulus is comparable to steel and iron. I agree that 'unbreakable' is clickbait even if it is quoted.

dhdhxhx• 11 years ago

That still doesn't mean anything useful. That's just a measure of how much it changes shape per unit force in its elastic phase. It gives no indication about how far it can go changing shape in a reversible, elastic manner before it starts to yield and undergo permanent deformation.

Now a stress-strain curve on the other hand, THAT would be useful.

shawkinaw• 11 years ago

Yeah, the only justification for 'toughness' was the Young's modulus, which does not tell you how resistant it is to breaking at all. And by that measure, sapphire [1] is 2.5 times tougher than steel [2].

[1] E = 7.4e7 psi (http://rubicontechnology.com/company/sapphire)

[2] E = 2.9e7 psi (https://en.wikipedia.org/wiki/Young%27s_modulus)

blt2• 11 years ago

Don't think it's nitpicking at all. I came away unsure whether the new material is hard (scratch resistant) or tough (won't shatter when dropped). An article about a new material that doesn't make the distinction fails fundamentally.

vlehto5• 11 years ago

You might find it interesting that toughness and "won't shatter when dropped" are different things.

Toughness(G) = slowly absorb energy without fracture.

Shattering is more dependable of:

Fracture toughness(Kc) = (E*G)^0,5

Where E = modulus. That explains why plastics with low E shatter easily while being tough. Metals have additional hardening methods that allow them to go beyond this rule.

PS. Your knowledge on the subject is already what I'd wish laymen had. So I really don't mean any offense.

wobbleblob• 11 years ago

Everything is breakable, given a big enough hammer ;)

Or time alone with my daughter! "child-proof" isn't a reassurance, it's a challenge

aryehof• 11 years ago

So many of us can identify with that, and so well stated!

such_a_casual2• 11 years ago

I wonder if it's safe to smoke out of.

FrankenPC• 11 years ago

COnsidering what it's made of, I imagine it has some pretty amazing thermal properties.

qnaal• 11 years ago

aluminum is a known neurotoxin

daughart• 11 years ago

Only at very high concentrations: Adverse neurological effects have been observed in rats and mice at doses of 100–200 mg Al/kg/day, while the USDA limit is 0.10–0.12 mg Al/kg/day for adult (25–30- and 70+-year-old) males and females. Aluminum is the 3rd most common element in the Earth's crust and humans have evolved given a certain level of environmental exposure. (http://www.atsdr.cdc.gov/toxprofiles/tp22-c2.pdf)

Johnny5554• 11 years ago

But is it as scratch resistant as hardened glass? Having glass that doesn't fracture when dropped is nice, but not if it means it gets scratched up from the keys in my pocket.

cordite• 11 years ago

A few questions on applicability

1. Would this be good for a car? Is having a mostly unbreakable windshield a good thing?

2. How would it handle for cookware? Will it last even if an ignorant person left it in the oven for hours on end?

3. What about uses on phones? Can I have both a scratch resistant touch screen that also doesn't fracture if I drop it 3ft onto asphalt?

4. What does it do in reaction to sunlight? How insulative is it if used in buildings and homes?

5. Is it non reactive for biomedical uses? Does it deteriorate over time? How stable is it?

govspy3• 11 years ago

2. How would it handle for cookware? Will it last even if an ignorant person left it in the oven for hours on end?

Pyrex has been around since the 1910s and doing this just fine ever since.

politician• 11 years ago

Well, Corning sold the brand name Pyrex around 2000. A post-2000 Pyrex item may not have the same composition as the Corning product you're more familiar with.

nly• 11 years ago

Pyrex will shatter if you take it out of a blistering hot oven and pour cold water on it (e.g. to let stuck on food soak).

mvgoogler• 11 years ago

Am I being overly cynical when I interpret: “We will establish a way to mass-produce the new material shortly ... We are looking to commercialize the technique within five years.” as "We have no clue how to mass-produce this but hope we can figure it out in five years if someone gives us money"?

It's hard to imagine how a gas-based "containerless processing system" will lend itself to producing the thin, uniform sheets of glass for windows or complex shapes like tableware.

It's a cool prototype, but figuring out how to produce at scale is often the hard part.

wycx• 11 years ago

Indeed. A method of making glass via a containerless processing system that I am aware of, is aerodynamic levitation, wherein a ball of starting material is suspended in a stream of gas, such as Ar, and heated by lasers. This method is used in systems that tend to crystallise rapidly rather than quench to a nice glass, since the thermal mass of the sample is very small and you can take all the heat away instantly by tunring off the laser. Samples prepared by such a method are typically 100s to 1000s of microns in diameter. I would be very interested to hear how they would scale this method to industrial production, if aerodynamic levitation is how they made their glass.

Overtonwindow• 11 years ago

Put it on an iPhone and it will shatter. Guaranteed.

hoodoof• 11 years ago

Make bottles out of this, sell them, return a deposit to get them back. Wash them. Reuse.

venomsnake• 11 years ago

This could revolutionize knife making. A steel knife is always like a saw on micro level. A glass (like obsidian) could get properly sharp. A glass with the properties of steel is a dream come true.

tb303• 11 years ago

Finally, we can keep humpback whales in our starships!

joehenriod• 11 years ago

Serious question, couldn't they have just used steel walls and grabbed the whales no problem?

I see no reason that they needed to be able to see through the walls and look at the Wales inside.

seesomesense• 11 years ago

Sorry, But That New Glass From Japanese Researchers Isn't Unbreakable

http://www.forbes.com/sites/carmendrahl/2015/11/03/sorry-but...

SixSigma• 11 years ago

I think the "containerless processing technique" is an acoustic levitator. My friend was on the team building one for a Japanese investor who wanted to make a wine glass that didn't break when you knocked it over on your fancy granite worktop.

See one working https://youtu.be/0K8zs-KSitc

fixxer2• 11 years ago

Please start with the iphone. Damn thing shatters if I look at it funny.

testrecord• 11 years ago

Man, I've never had a problem with a broken iPhone screen. I worked for months on a pretty large construction site breaking up concrete while dropping my phone fairly regularly and it's still aces.

Obviously a stronger screen would be great, but a case does wonders if you want a functioning phone for now.

fixxer2• 11 years ago

yup, hindsight...

I never had a problem with a phone screen breaking until the 6 plus. My OnePlus is bulletproof.

infinity0• 11 years ago

I bet the British government will try to ban this too.

tcpekin• 11 years ago

Here's a link to the paper itself if you have access: http://www.nature.com/articles/srep15233

Scientists develop 'unbreakable' glass almost as tough as steel

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