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Bizarre Properties of Glass Allow Creation of "Metallic Glass" 265

Posted by ScuttleMonkey
from the wonder-woman-unavailable-for-comment dept.
VindictivePantz writes to mention that scientists have discovered some bizarre properties of glass and are already applying that knowledge to create what is being called "metallic glass." "The breakthrough involved solving the decades-old problem of just what glass is. It has been known that that despite its solid appearance, glass and gels are actually in a 'jammed' state of matter — somewhere between liquid and solid — that moves very slowly. Like cars in a traffic jam, atoms in a glass are in something like suspended animation, unable to reach their destination because the route is blocked by their neighbors. So even though glass is a hard substance, it never quite becomes a proper solid, according to chemists and materials scientists."
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Bizarre Properties of Glass Allow Creation of "Metallic Glass"

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  • Beam me up, Scotty!
  • Is this the aluminium glass that Scotty spoke of?
  • by Zero__Kelvin (151819) on Monday June 23, 2008 @05:09PM (#23910075) Homepage
    It's not "Metallic Glass", it's Transparent Aluminum ...
    • Either way, be prepared to see them as band names any minute now. Or perhaps the band name is "Metallic Glass", thier first album is "Transparent Aluminum"
      • by pipingguy (566974) *
        There's a band called Air Liquide, apparently...
        • Re: (Score:2, Funny)

          by Llamalarity (806413)
          "Air Liquide" Never heard of them. Let me guess - Too much LDS in the 60s?
          • Re: (Score:3, Funny)

            by Entropius (188861)

            I think you mean too much LSD.

            The LDS are those scary people with nametags that act vaguely robotic that keep knocking on your door.

            • Re: (Score:3, Funny)

              by graphicsguy (710710)
              Whoosh!
            • Re:New band names. (Score:5, Informative)

              by mosb1000 (710161) <mosb1000@mac.com> on Monday June 23, 2008 @10:38PM (#23912569)
              For those of you who don't know, that use of the LDS acronym is a refrence to Star Trek IV (the source of all this transparent aluminum talk).

              I know these posts are not serous, but the term metallic glass does not refer to transparent metals, but rather metals with an amorphus structure. Metallic glass lacks the fracture points associated with the crystal lattice of metals. This means that metallic glass does not fagigue over time as normal metals would. I believe that metallic glasses were first discovered by rapidally cooling laminants of titanium (I think I read somewhere that a WW2 nazi scientist fisrt discovered them).
          • Re: (Score:2, Funny)

            by Walkingshark (711886)

            As a former Mormon, I can tell you that ANY amount of LDS is often too much LDS... (and yes I know its a movie quote)

      • by ross.w (87751)
        Then someone else will have a similar sounding band name and they'll be forced to switch the album title and the band name on the first album. Flowers is a stupid name for a band anyhow.
    • Re: (Score:3, Funny)

      by CMF Risk (833574)

      Screw all your Trekkies!

      Transparisteel
      http://starwars.wikia.com/wiki/Transparisteel [wikia.com]

    • by celtic_hackr (579828) on Monday June 23, 2008 @09:23PM (#23912103) Journal

      Glass is Silcon based,
      Transparent Aluminum is Aluminum based, it is also known as the gemstone White Sapphire and looks much like diamonds. In fact it has been used for diamond like effects, but doesn't have the brilliance of diamonds (due to different reflective indexes).

      Glass MOHS: ~ 5.5
      Transparent Aluminun: MOHS = 9. Much harder, better crystaline structure, denser.

      And as far as the article's claims, all solids move, but glass definitely is an abnormal material.

  • So am I (Score:5, Funny)

    by UnknowingFool (672806) on Monday June 23, 2008 @05:10PM (#23910095)

    is a hard substance, it never quite becomes a proper solid, according to chemists and materials scientists.

    So am I according to an ex-girlfriend. Thanks, I'll be here all week. Try the veal. Tip your waitstaff.

  • Scotty... (Score:5, Informative)

    by WolverineOfLove (1305907) on Monday June 23, 2008 @05:11PM (#23910101) Homepage Journal
    My first thought is transparent aluminum from Star Trek IV. Only to discover we're closer than I'd think... [wikipedia.org]
  • by leob (154345) on Monday June 23, 2008 @05:14PM (#23910141)
    The deceptively liquid-like behavior of glass can be seen when you look at glass in the windows of an old building. The glass begins to sag and distort internally over the centuries, due to the effect of gravity.

    This is crap. [wikipedia.org] There have been windows of old buildings "sagging" upwards. The old technology of making windowpanes resulted in glass of uneven thickness, and it makes sense to install it the thick side down. Sometimes the installers did not care enough.

    • by ErkDemon (1202789) on Monday June 23, 2008 @05:22PM (#23910231) Homepage
      Yeah, when you're assembling irregular-thickness glass for stained glass windows, you put the thicker (heavier) end at the bottom. It makes the glass mounting more stable, and the glass less likely to fall out.

      For larger sheets, you put the thicker (stronger) end of the glass sheet at the bottom, because the bottom of the sheet has to carry the weight.

    • by Anonymous Coward on Monday June 23, 2008 @05:38PM (#23910415)

      And not only that, the nonsense about glass not being solid because it isn't crystalline is another oft repeated chestnut that is incorrect. There are plenty of non-crystalline solids, like wood, bone, cement, and pink and white iced animal cookies. Also pancakes. A soft solid, yes, but solid nonetheless.

      You could even make a case that silicon in its pure, glassy state is already a form of "metallic glass". It certainly looks like it.

    • Re: (Score:3, Insightful)

      by MightyYar (622222)

      This is crap.
      Yeah, I can't believe they repeated this little urban myth. The whole article takes a huge credibility hit IMHO.

      Not to mention how the last half is written so poorly that it ventures into incomprehensibility-land.

      • Re: (Score:2, Informative)

        by pjhenley (98045)

        As a further nit-pick, I'd note that icosahedrons are not made from pentagons. I think they mean dodecahedrons, the faces of which are pentagons:

        An icosahedron is like a 3-D pentagon, and just as you cannot tile a floor with pentagons, you cannot fill 3-D space with icosahedrons, Royall explained. That is, you can't make a lattice out of pentagons.
    • Gel (Score:4, Insightful)

      by Psychotria (953670) on Monday June 23, 2008 @05:42PM (#23910469)
      Additionally, I am wondering why the summary compares glass to gel. Gel is a colloidal solution.
      • Re: (Score:3, Informative)

        by wattrlz (1162603)

        If you discount the medium gel could be considered a, -for lack of a better term- jammed precipitate. The whole point of TFA was that gel can be used to model the particle-interaction that takes place in glass because both can't settle into a more stable state.

    • by Red Flayer (890720) on Monday June 23, 2008 @05:43PM (#23910489) Journal
      You're right, it is crap... except that the effects we observe were due to the liquidity of glass... albeit when the glass was molten :)

      There is another distortion effect that myth attributes to liquid flow of glass... if you observe old architectural glass, you may note "waviness" in the glass. This is cause by how sheet glass was made.

      A leader is dipped into molten glass, then raised slowly. While the glass is pretty much of uniform thickness, there is distortion caused by variations in temperature as the sheet cools.

      If you're looking at old houses, it's interesting to note what kind of distortion is present in the windows -- this can tell you how the glass was made, which in turn can tell you if it's likely that the glass is original to the house. One needs knowledge of the history of window fabrication, which is often regional... but I digress.

      This is yet another example of something making sense, but not being accurate. Yes, glass is technically liquid. But, the flow rate is such that the effects we attribute to the liquidity of glass would take millions and millions of years to occur at STP. Typically any effects in glass that are due to liquid flow occurred during the hardening stage.
    • by buddhaunderthetree (318870) on Monday June 23, 2008 @05:47PM (#23910537)

      Bingo. If glass flowed at any rate the glass vases found in Egyptian tombs would have been puddles. I can't believe this stuff still gets repeated.

      • You should read that section of the wiki article, it's pretty interesting. I especially like the line To observe window glass flowing as liquid at room temperature we would have to wait a much longer time than the universe exists. Heh. Some glasses do flow more freely at room temperature though, apparently. Probably not so quickly that you'd see it with your eyes though.

        • Re: (Score:3, Informative)

          Just a couple of asides. There are plenty of cases where obsidian aka volcanic glass has been found with sharp undeformed splinters in geological settings, where it cannot have been disturbed for many millions of years hence the inference is no significant flow occured. There is also the Pitch Drop experiment, showing what a proper fluid will do.. http://www.physics.uq.edu.au/pitchdrop/pitchdrop.shtml [uq.edu.au] I presume since it's not mentioned there has been no deformation and flow of the glass funnel...
      • Re: (Score:2, Redundant)

        by Khyber (864651)

        Not true. At room temp it would take MILLIONS of years for the glass to distort, not a mere few thousand. This can be tested by checking the viscosity of glass at different temperatures.

      • by gillbates (106458) on Monday June 23, 2008 @11:04PM (#23912749) Homepage Journal

        I can't believe this stuff still gets repeated.

        It gets repeated because this particular tidbit of misinformation happened to make it into a very popular undergrad chemistry textbook:

        Glass is a complex mixture of silicates and is classified as an undercooled liquid.

        College Chemistry with Qualitative Analysis, Sixth Edition, Nebergall, Holtzclaw, Robinson. p743, section 27.12

        It didn't take much of a stretch, no pun intended, for the explanation of thickening of the bottom of cathedral windows to include this little tidbit.

    • by Karloskar (980435) on Monday June 23, 2008 @05:56PM (#23910605)
      There are lenses in very old telescopes that still function perfectly. If glass flowed at room temperature they would become distorted.
      • Re: (Score:3, Insightful)

        by xlation (228159) *

        Clearly.

              It's not uncommon for amateur telescopes to have mirrors accurate to within 1/10th of a wavelength. If glass flowed, it wouldn't take it very long to go out of figure.

      • Re: (Score:2, Redundant)

        by Khyber (864651)

        Glass does flow at room temperature. It would just take millions of years instead of a thousand years for you to notice. Glass at room temperature has a viscosity so high you can't perceive the flow without an electron microscope. Get that glass to about 1300 degrees Fahrenheit and you can mold it like slightly-hard silly putty.

    • by JustinOpinion (1246824) on Monday June 23, 2008 @06:30PM (#23910923)
      Yup. That myth has been thoroughly debunked, yet it still gets repeated.

      The article is full of meaningless or incorrect statements. Like:

      Royall is part of a group of scientists who think that if you wait long enough, perhaps billions of years, all glass will eventually crystallize into a true solid. In other words, glass is not in an equilibrium state, (although it appears that way to us during our limited lifetimes).
      As a researcher in the field, I can assure you that this isn't a controversial statement. We all agree that glasses are not at equilibrium. We all agree that the low-energy state for glasses is to crystallize, and that (in principle), if you wait long enough they will crystallize. The questions revolve around details like "how far from equilibrium?", "what are the implications of being non-equilibrium (e.g. on phase transitions)?", "what are the kinetics and dynamics?", "how long would it ~actually~ take for a given amount of change/flow/reconstruction/etc.?"...

      Also, equating "equilibrium" with "being a solid" is total nonsense. (Solids, liquids, and gases can all be at equilibrium or far from equilibrium...)

      In short, don't waste your time with this ridiculously hyped review of some otherwise interesting (but not revolutionary) science.
  • misleading (Score:3, Informative)

    by retech (1228598) on Monday June 23, 2008 @05:15PM (#23910153)
    The term glass refers to the structure/lattice. Not to the substance we commonly refer to as glass.
  • by edwebdev (1304531) on Monday June 23, 2008 @05:24PM (#23910261)
    One of the interesting aspects of this article is how it highlights the usual thermodynamic balance between entropy and free energy. States of matter in the equilibrium phase attempt to simultaneously maximize entropy, a measure of the statistical likelihood of a given state, and minimize the amount of energy "stored" in the given arrangement of molecules.

    The most favorable condition is often a compromise between maximum entropy and minimum energy as highly ordered states, such as tetrahedral or other crystalline arrangements, often act to reduce the amount of stored energy due to minimized interatomic and/or intermolecular interactions and related factors. Pure crystals of substances will often form because the energetic "advantage" of the highly ordered crystalline state is often great enough to overcome entropic barriers.

    The model that the researchers propose is interesting because the crystalline state itself introduces a degree of energetic disadvantage due to what is described as "cramming" of the individual crystalline unit cells. I wonder what models they used to form their hypothesis that the glass would eventually form a perfectly crystalline state.
    • Re: (Score:3, Interesting)

      by mapsjanhere (1130359)
      Hmm, I usually see that as a typical case of kinetic over thermodynamic control. The material hardens faster in the higher energy state instead of slowly rearranging to the lower minimum.
      The article has a serious flaw so in claiming that glass formation helps with fatigue; the main reason that you get metal fatigues is loss of ductility. Most glasses are brittle to begin with, and even if not, the same forces that allow crystal growth leading to embrittlement are active in the glass too.
      • Most glasses are brittle to begin with, and even if not, the same forces that allow crystal growth leading to embrittlement are active in the glass too.

        Hruh? That's not true at all, from what I recall. Glass is by definition uncrystallized... I mean, there's a bonding structure, but it's disorderly...

        Am I missing something? It's been a while, but I think that still holds.

        As for glass formation helping with fatigue, it's a matter of the disordered state being stable enough that it requires more energy (

  • by Anonymous Coward
    This reporter does not know what they are talking about. The comet failed due to stress risers at the corners of the windows, not because of grain boundaries. Let the materials scientists do the writing. Don't let journalists do science writing. Morons.
  • by anmida (1276756) on Monday June 23, 2008 @05:32PM (#23910349)
    First of all, we've known about metallic glasses for years. There's a melt-spinner in the basement of my matsci building that we use to make metallic glasses. Their properties have been fairly well-studied.

    Second of all, I don't really like the experiment that these people conducted. They simulated atoms during solidification, but they used microspheres within ANOTHER medium. With glasses, during there is no matrix material within which other molecules are moving. I find their model and extrapolation to be questionable. We are still trying to thermodynamically understand the glass transition and the solid amorphous state compared to the solid crystalline state.
    • Re: (Score:3, Interesting)

      by blair1q (305137)

      What's so hard to understand?

      Quantum physics tells us that electrons prefer certain geometric arrangements about a nucleus.

      Due to this, atoms prefer certain geometric arrangements that take advantage of this atomic-orbital energy function. If this allows for a repeating pattern, and the mechanical noise in the system is high enough to disrupt any non-optimal bonds, a repeating pattern will most likely form.

      But if the gross arrangement of several atoms is stable to thermodynamic perturbation even though som

      • by anmida (1276756) on Monday June 23, 2008 @08:18PM (#23911781)
        Yes, dear. I know that. However, there's some weird shit with the glass transition, in that it looks like a second-order thermodynamic transition, but it isn't. The volume and enthalpy of glass goes from that of it's kindred solid to that of a liquid, with the smooth glass transition joining the two regions. I think a big issue that needs to be discussed is, what exactly is a solid? The glass guys have an easy way of determining a solid: viscosity. If it has enough resistance to flow, they define it as a solid.
  • In my very best Canadian/pseudo-Scottish accent, "Hello computer..."
  • by hAckz0r (989977) on Monday June 23, 2008 @05:38PM (#23910421)
    Look at the plate on the front of those those golf club drivers that they won't let you use, or even this patent:
    http://www.google.com/patents?id=Kq4yAAAAEBAJ&dq=4256039 [google.com] Filing date: Jan 2, 1979


    Its also been used in large transformers for years. The "technology advance" here worth noting is in being able to produce it while casting/moulding objects that are not thin and flat. It had been done as sheets for years, but casting a part that is something like 7 times the strength of titanium is much more useful. Unfortunately, the problem to solve is its brittleness. Things that shatter are much less useful.

  • BMG (Score:5, Interesting)

    by Composite_Armor (1203112) on Monday June 23, 2008 @05:39PM (#23910431)
    I am a materials engineer at the University of British Columbia in Canada. I recently did a technical presentation on 'Bulk Metallic Alloys' which seems to be the category of materials this 'glass' falls into. BMG's are very exiting materials, their main advantage over traditional alloys is their ability to store energy in elastic deformation. Esentially, they are the worlds best spring material. However; Be careful with your application in using these materials, they may have properties of strong alloys, but they have failure characteristics simmilar to ceramics. Usually they can fail with little to no warning, and catastrophically at that. Crack formation cannot be tolerated. I would not be comfortable with using this material for plane wings. Possibly the landing gear. This material has its niche in underplating for bodyarmor. Send the bullets back. For more information, a good website is http://www.liquidmetal.com/ [liquidmetal.com]
  • Let's Make Chips! (Score:3, Insightful)

    by Doc Ruby (173196) on Monday June 23, 2008 @05:39PM (#23910435) Homepage Journal

    Silicon [wikipedia.org] is a metalloid [wikipedia.org], which has some properties of a metal (or some degree of those properties), and some properties that nonmetals have instead. That's why it can be made into a semiconductor.

    That isn't news. This is the big story of 20th Century technology. Exploiting the glass properties of this metalloid is the real news.

  • wow, just confusing... glass slow liquid... just confusing...

    Thanks, No-Child-Left-Behind!! LOLz

  • by topham (32406) on Monday June 23, 2008 @05:53PM (#23910575) Homepage


    Transparent Aluminum isn't fiction and never was.
    Al(2)O(3) is sapphire. Personally I wear a watch made of Titanium and Sapphire.

    • Supposedly transparent aluminum is highly scratch resistant. I'd like to see it used in PDA, cellphone, and Gameboy screens.

      • Re: (Score:3, Interesting)

        by dhovis (303725) *

        Supposedly transparent aluminum is highly scratch resistant. I'd like to see it used in PDA, cellphone, and Gameboy screens.

        Sure, if you don't mind paying thousands of dollars for your PDA, cellphone or Gameboy. Sapphire (not transparent aluminum, see above rant) is much more expensive to produce than ordinary (silica) glass. That is why it gets used in high end watches (glass is hard to scratch, but sapphire is even harder still). The other major use is in supermarket barcode scanners. In that application, glass would get scratched up way too quickly by cans, glass bottles, etc. So they use sapphire plates on top of gl

    • by dhovis (303725) * on Monday June 23, 2008 @06:59PM (#23911203)

      Please, no.

      Single crystals of alumina (Al2O3) are transparent. They are known as sapphire if clear or blue. With slight chromium impurities, they are known as ruby. They are a ceramic, not a metal. There are three oxygen atoms for every two aluminum atoms, which makes it 60%at oxygen. It is not aluminum. It would make more sense to say your watch is made of oxygen, but not by much.

      Just saying "aluminum" implies the metallic structure, which will never be transparent despite the fervent hopes of many a Star Trek fan. The inherent availability of free electrons in the conduction band of metallic aluminum will ensure that is will not be transparent in any thickness greater than a few hundred nanometers. Truly transparent, metallic aluminum would be a breakthrough on par with a working transporter.

      IAAPhDMS (I Am A PhD in Materials Science), and this has been your Pedantic Slashdot Rant from a Expert(TM) for today.

      Back on topic. These metallic glasses (Vitraloy and the like) have been around for a decade now and have very interesting properties. They are not, however, transparent. Not even a little bit.

  • by breem42 (664497) <breem42&yahoo,ca> on Monday June 23, 2008 @05:57PM (#23910611)

    Aside from repeating the old myth that glass can actually sag over hundreds of years, the article says very little. Perhaps a bad summary.

    The jist of linked the story is:

    A group of scientists in Bristol, Canberra and Tokyo used a material (doesn't say what) analogous to glass, not glass. This material is easier to study. Using this material they claim they were able to understand better what happens on the atomic level as it solidifies, and why it never really becomes a crystal. Nowhere in the article does it explain why this will lead to "metallic glass"

    Here [nature.com] is an abstract for the original article. Pretty complex wording, but nothing about metallic glass.

    • Metallic glass is interesting but was probably predates most people reading this. I got a free sample of an iron based metallic glass that was manufactured on an industrial scale in 1986. I think the name of the manufacturer was "Allied Metals" and the material was intended for transformer cores. To make such stuff you need cooling rates of several hundred degrees per second. That sounds difficult unless you consider something like pouring molten metal onto a water cooled spinning copper cylinder to mak
  • by PPH (736903) on Monday June 23, 2008 @05:57PM (#23910617)
    ... residents of glass houses may now throw stones.
  • by phrostie (121428) on Monday June 23, 2008 @06:30PM (#23910913)

    "Royall is part of a group of scientists who think that if you wait long enough, perhaps billions of years, all glass will eventually crystallize into a true solid."

    tell me a decent geologist cant locate some billion year old glass from a meteor impact, a volcanic eruption or something.
    if you can find a sample you should be able to test this.

  • From TFA:

    An icosahedron is like a 3-D pentagon, and just as you cannot tile a floor with pentagons, you cannot fill 3-D space with icosahedrons, Royall explained. That is, you can't make a lattice out of pentagons.

    An icosahedron has triangular faces. You were thinking of a dodecahedron, perhaps, which has pentagonal faces? The icosahedron's only relation to anything pentagonal (that I'm aware of) is that its dual polyhedron happens to be a dodecahedron.

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