Amorphous Steel

pfdietz writes "Researchers at Oak Ridge have achieved a holy grail of materials science: they have figured out how to produce amorphous (glassy) steel. The material is reported to be twice as hard and have twice the tensile strength of the strongest ultra-high tensile strength steel alloy."

Comments

Somebody explain this to me?

[orthogonal]

From the linked article: Steel, an alloy of mostly iron atoms with varying amounts of carbon and other elements, is ordinarily a crystal, with an internal structure consisting of neat rows of atoms. If produced quickly from a liquid phase, however, a disordered solid can result.

Ok, somebody who understands materials science explain this to me, please: is the amorphous steel's hardness and strength greater because the non-amorphous, crystalline steel breaks easily along a row of atoms, as if along a perforation, while the amorphous steel, lacking such an orderly structure, lacks long runs of bonds along which breaks can be easily made?

Pictorially, is it like this?

Fe-Fe-Fe-Fe regular, non-amorphous steel
|..|..|..| <--- break along this line
Fe-Fe-Fe-Fe

Fe-..-Fe-.-Fe amorphous steel
|.\-Fe-Fe/.| <--- no natural breaking line
Fe-Fe-Fe..-Fe

Re:Somebody explain this to me?

[furry_marmot]

There was an article in Discover magazine just a couple of months ago about this very thing. Not sure if it's online, but you can definitely find it at your local library.

One thing worth noting: While the tensile strength is increased greatly, it is also glass-like in that if you hit it with a baseball bat, it explodes in lots of little shards. It has to do with the lack of a lattice structure keeping it together.

Another thing I thought was interesting: steel knives sort of shed molecules and become deformed at the knife-edge when you use them, requiring you to sharpen them. Glassy steel knives wouldn't do this. You could literally pour yourself a knife in a mold and have a never-dulling knife -- assuming you don't drop it. :-)

You could use it the same way we use glass

[Spamalamadingdong]

To avoid the shattering problem, you could use lots of metal fibers in a matrix of something else (say, resin). This would give you the possibility of an injection-molded steel-fiber composite bicycle frame. (Why you'd use steel instead of glass or carbon, I don't know - but it would be possible.)

I can see the glass issue as a problem for some of the proposed uses, though. To retain its strength it would have to avoid crystallizing; if you used it for beams in a building, you would have to guarantee that a fire could not raise the temperature high enough long enough for the material to begin crystallizing. Once that happens, all your wonderful high-strength properties are ruined and you have to replace all that steel (assuming the building survives).

Thank you ...

[gstoddart]

For re-affirming my faith in Slashdot. I was thinking the exact same thing. =)

However, all kidding aside ....

By 'glassy', can anyone shed light on this actually infers? I'm thinking more to do with material versus optical properties. (Yes, I R'd TFA, and they certainly don't say anything about optical properties.)

Liquidmetal mentioned in Discover article

[Macross]

In the Discover article, one of the companies attempting to capitalize on amorphous metals is LiquidMetal. The stuff has been used in Head tennis rackets, golf clubs, hinges in cell phones, etc. A friend of mine has tested the head racket and he said you can really feel it return the energy better than other rackets.

Although the Discover article says that knives can be easily cast (e.g., for surgical purposes, disposable knives can be made much more easily), the metal isn't as hard as hand-made knives. This is sort of surprising given its glassy properties -- the ads by Liquidmetal show a steel ball bouncing for minutes on a slab of the stuff.

See this link http://www.rayrogers.com/lm.htm for one knifemaker's experience in dealing with the stuff (the RC rating is in the mid 50's if I recall). Still very promising technology though. Once the cost comes down I think it will have a very wide range of applications.

Re:Thank you very much!

[Kevin Burtch]

I used to work in a machine-shop, both in design and in purchasing (for several years).

Reynolds and many others consider 6061 and 6063 to be marine-grade.

They also consider 7075 to be aircraft grade... twice the shear and tensile strength of 6061, but also twice as expensive (cost/lb).

The T-rating ("-T6") is a hardening that it receives after forming, irrelevant to the alloy.

As far as what is spec-ed out, I agree... you should be able to use 6k series in an airplane, for example in a coffie-pot-holder.
Oddly enough, we made a run of those for an airline, and they spec-ed it had to be 7075-T6.
And people wonder why air-fare is so expensive... bozos are making the decisions.

The reverse is true too... we made a run of bicycle crank-axles that were spec-ed to be 7075-T9! Hardly an airplane, but those puppies sure were expensive!

Re:Great. Now how will we fight the Robots...

[ikkonoishi]

tuning forks.