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Science Technology

Super Hard Steel 37

Sub_Dude writes: "Seems the folks at a Dept. of Energy lab have come up with a way to coat steel to make it harder. The process might be interesting to mechanical engineers out there, and because the article mentions nanotechnology, Hemos will like it. The press release is here, and an award for being "one of this year's top 100 technological achievements" is here."
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Super Hard Steel

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  • The article says that the steel can handle up to 16 Gpascals. That is equivilent to over a thousand TONS per square inch. That's a goodly amount.

    The articles listed seems like some sort of press release. Is there any sort of independant verification available? I assume there has to be if R&D Magazine is willing to give them an award for this.

    • Michael posted: "The press release is here [inel.gov]"

      You replied: "The articles listed seems like some sort of press release."

      READ this again, and think about it.

      Sometimes the posts just moderate themselves...

  • As mentioned in some of Julian May's SF books.

    Cool :).
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  • by Anonymous Coward
    Super Hard Steel(tm) ... it's what the ladies like to call me.

    Unfortunately I am also known as "nanotube."
  • The lead in story here contains some innacuracies :(

    1. The actual press release mentions nothing about nanotechnology, it simply mentions units of size as follows:

    Alternatively, for specific applications researchers can heat the coating to create a stable structure made up of crystal grains from 2 to 75 nanometers in size, only slightly larger than a single atom. "This approach is a much more robust route to forming nanoscale crystalline structure ...."

    2. The process does make steel harder but only in the sense that it makes the **surface of the steel** harder via a bonded coating. The process does not make the steel structurally stronger according to the article. It just makes for corrosion resistence and such.

    Ummm I've never modded anything here or voted but is this really front page stuff???
    • So, what are your relative fields?

      My degree is in Mechanical Engineering. To me, at a glance, Kibo sounds like he knows what he's talking about but should never become a teacher because he's not very good at explaining it.

      TechnoGrl seems to avoid saying anything new or explanatory so that nothing she says could be wrong... and somehow it doesn't sound like her field is Material Engineering.

      My upshot goes something like this: Hardness and strength (but not toughness) have a very high correlation. However, having something very strong painted onto something weak doesn't make the whole object miraculously very strong - sorta.

      Try to pull it apart and it won't make too much difference (depending on paint thinkness) bending it will make more difference, but it's probably still too thin. More importantly, though, it won't be able to form little cracks when you bend it back and forth. So the lifetime of this part, even without having a dramatic effect on the bulk strength of the material in a single test, can be very dramatic over a period of time.

      And of COURSE that's vague. I only wrote a paragraph in something people get graduate degrees in forchristsakes.

    • Not SO inaccurate. (Score:3, Informative)

      by Kibo ( 256105 )
      The nanotechnology in question is the production of nanoscale materials. But it can also refer to the thermal spray process [sunysb.edu] which is used to form the nanoscale materials.

      As far as hardness and strength. They harder a material is the stronger it is. The actual relation isn't trivial to derive and depends on things like the tip you use for intentation, qualitatively, it isn't that difficult to grasp so I'll do my best to explain. Strength is the ability of a material to resist plastic deformation. Plastic deformation is when you stretch a material and it won't snap back, as opposed to elastic deformation where it will. Try bending a paper clip, very little at first, it will snap back like you never touched it. Now bend it around. Where you bent it, the bumps and twists, are now harder and resist bending more than the rest of the paper clip and make it look irregular. That's plasitically deformed. It won't ever be like it was unless you remake the paper clip. If you bend it a little more it should get a little bit harder, then stiff and easy to break. That's a qualitative stress-strain curve you can feel. Then same thing happens when you push an indentor into a material, some of it gets pushed out of the way to make room for the indentor, which isn't all that different from bending the paper clip. In fact hardness is so closely related to the strength of a material you can do a surface hardness test to find out what alloy something is made of without destroying it. One of those things. On the other hand, this is a coating, so it's always on the surface of something, and in that sence you're right. Hard coatings typically need less lubrication, experience less fretting (a form of mechanical corrosion), etc. They also mention that it has self-sharpening characteristics. So it might find its way into new anti-armor weapons, or just the sharper image catalog.

      Yeah I would say this is front page stuff. Getting a metal to come near the theoretical ideal in strength is pretty impressive. This is at least as front page as anything else up there. A good overview of thermal spray can be found here [ewi.org].

      • >The nanotechnology in question is the production >of nanoscale materials. But it can also refer to >the thermal spray process which is used to form >the nanoscale materials.

        Just because something has the prefix "nano" in it does not mean it is related to nano technology. Whereas nanotechnology concerns itself with the manufacture of ultra small machines, both the article and the links that you provided merely refer to the production of nonometer sized particles used as a coating. This is not nanotechnology.

        >As far as hardness and strength. They harder a >material is the stronger it is.

        I am afraid that you are incorrect. Diamonds for examply are incredibly hard but are also extremely brittle and hence are not used in places where structural strength is required.

        >Yeah I would say this is front page stuff. >Getting a metal to come near the theoretical >ideal in strength is pretty impressive

        I agree. Unfortunately the actual article made no such claims. They did not invent a stronger steel. They merely invented an extremely durable coating which bonds to steel. Sort of like a "super paint" actually.

        • I want to be Todd Bridges.

          Dictionary.com might agree with you, almost. But I would consider it to be technology on the scale of a billionth of a meter. So I prefer a more liberal interpretation. Certainly the materials are nanoscale, nanophase, and state of the art. I wonder if you'd feel the same about nanoarchitectured materials?

          I am afraid that you are incorrect. Diamonds for examply are incredibly hard but are also extremely brittle and hence are not used in places where structural strength is required.

          This is where it gets fun. You're confusing hardness or strength (they ARE interchangable ask ASM [asm-intl.org] or your favorite Mechanics of Materials textbook), and Toughness. Toughness is the ability of a material to resist cracking, or if you prefer how brittle it is. Diamond is most certainly the king of strength, but, as you astutely observed, is brittle. Sillicon Carbide, carbon fiber, as well as glass share this quality. Again, I can't stress this enough, don't take my word for it. Tell me I'm full of shit, goto this website [powells.com] and find out for yourself.

          Unfortunately the actual article made no such claims. They did not invent a stronger steel. They merely invented an extremely durable coating which bonds to steel. Sort of like a "super paint" actually.

          They did invent a stronger steel. It happens to be a coating, but with a strength of I think 16 GPa, which is about 16 times better than a typical high strength structural steel and in the realm of about theoretical. Considering they believe the coating to be all but free of defects, this actually makes a lot of sence, as it is the defects which start the cracks that limit the strength of a material.

          But it's funny, how people are. I prefer a liberal interpretation of nanotechnology, but ridgedly adhere to the indoctrination I was educated under. In anycase it certainly seems the press release was written with a reader like me in mind, and in so far as that was a good choice, it is correct. I would have expected it to have less resistance to chemical corrosion, but material science can be counter intuitive. In anycase I'm sure Powell's has at least a few good books on mechanics of materials if you're into that kinda thing.

          • This is where it gets fun. You're confusing hardness or strength (they ARE interchangable ask ASM or your favorite Mechanics of Materials textbook), and Toughness. Toughness is the ability of a material to resist cracking, or if you prefer how brittle it is.

            Asking ASM as you suggest is dufficult because that website that you posted contains no facility at all for such definitions. I do not understand why you referred me to it.

            However this materials site:

            http://web.singnet.com.sg/~elite74/Glossary.htm

            Clearly defines hardness as :

            The measure of a material's resistance to deformation by surface indentation or by abrasion.

            You will note there is no reference to structural stregnth here as you suggest.

            Further more a simple search of that page will reveal that several definitions givin clearly differentiate between the terms hardness and strength by using them as follows:

            Overaging.:During precipitation hardening, aging beyond the point at which strength and hardness are at their maxima.

            Additionally, the second link that gave to support your argument was merely a link to Powells Book Store providing a list of books about Engineering and their prices which has nothing at all to do with the definitions of hardness or strength

            SO I am afraid that, dispite the useless links that you posted the terms hardness and strength are clearly two different things.

            I am sorry but clearly you are wrong and were just posting wild goose chase links in an effort to cover this up. As an Engineer, and I can see clearly that you are not, I tend to follow up on such things when warrented - which I can also see they no longer are.

            My original assertion still stands, that the article was innacurate in maintaining that a "stronger steel" has been created - it was merely a harder coating bonded to steel.

            • Tom Leykus [blowmeuptom.com] is right, people just want to be treated like shit. But despite evidence that supports his theory, IN THIS THREAD, I will once again try to be decent.

              From Mechanical Metallurgy by George E. Deiter 3rd Ed.

              The hardness of a material is a poorly defined term which has many meanings depending upon the experience of the person involved. In general, hardness usually implies a resistance to deformation, and for metals the property is a measure of their resistance to permanent or plastic deformation. To a person concerned with the mechanics of material testing, hardness is most likely to mean the resistance to indentation, and to the design engineer it often means an easily measured and specified quantity which indicated something about the strength and heat treatment of the metal.
              -- pg 325. Ch 9-1

              After that the chapter briefly discusses how the different tests work, and some light derivation including a special case of finding the tensile strength. (Incidently, this conversation is why I provided a link to Powell's collection of Mechanics of Materials texts; I wanted to avoid it.) A link to convert hardnesses for steel into tensile strength. [netcom.com] I might remark that given strength is simply a load over an area for a certain event, and any hardness test also uses a load over a slightly more complicated area (with some other considerations) one might readily and correctly assume they can be related. I might further add, that MY contention that strength and hardness are related is not even addressed in any of your definitions. I feel little need to offer anything in the way of proof, but since you seem to require it, this web site [netcom.com] might be illuminating. Also any materials, and most mechanical, engineering departments will have a similar poster in their hardness testing labs.

              Don't think me cruel, as I don't intend it in this fashion, but I had noticed the ASM site had a section called "Ask ASM" where you can pose questions, and thought it clearly marked. I suppose you could also write your local physics, mechanical, civil, or materials engineering departments as they almost certainly answer all sorts of questions. They are typically given to grad students to answer in math and physics departments.

              I'm sorry you didn't see the value in links that I hoped you would find useful. I tried my best to keep everything simple and accurate, I hoped others would find it interesting. But it would seem you have little if any interest in finding answers, which is fine. But if you're not going to seek illumination beyond that of a poor dictionary, for the life of me I can't see why you quibble with mine. The fact is they created a new phase of steel (I took this as an obvious point from the press release, clearly I was in error). If you still believe they did not, you MUST also believe glass and quartz are the same. Which is your perogative. A new phase is better than simply a new alloy, as their figure of 16 GPa certainly shows. As a final token, here is a Iron-Carbon (Steel) phase diagram [colostate.edu], note the lack of an amorphous phase (I realize it is quite busy, but it at least shows what steel fundementally is). In closing, you see what everyone else does, what you want to. Maybe this is what I get for picking nits.

              • You have diverted from the main point

                From the orignal press reease release (helps to read the linked articles):

                Branagan sees the possibilities for coatings like his to be nearly endless because all areas of industry experience wear and corrosion problems. ....Over the next year, Branagan will work with a range of industrial partners to conduct proof-of-concept tests, putting his coating through extensive erosion, corrosion, and fatigue testing.

              • A good introduction into hardness can be found at http://www.calce.umd.edu/general/Facilities/Hardne ss_ad_.htm [umd.edu]. It also contains a chapter on the relation between hardness and tensile strength (scroll down to section 7) which contains the following paragraph:
                A correlation may be established between hardness and some other material property such as tensile strength. Then the other property (such as strength) may be estimated based on hardness test results, which are much simpler to obtain. This correlation depends upon specific test data and cannot be extrapolated to include other materials not tested.

                Note esp. the last sentence!
  • It might be useful to note that it's not only the hardness of the material that's getting the industry to sit up and take notice. While, the material is harder than practically anything out there (there may be exceptions - all comments are welcome, but remember that it did wear down a Silicon Nitride pin), it's the cost that's also appealing. Super Hard Steel, while being a new concept scientifically, is not an exotic material (in the sense that exotic materials are expensive and difficult to prepare) because it's relatively easy to make; it's apparently made from the transformation of steel alloy (more details in the press release about it's manufacture would have been nice - none of this "coaxing mother nature" bullshit). It's extreme hardness and toughness, combined with a low coefficient of friction means that cost savings will also occur over the lifetime of the part because it lasts longer and requires less maintenance.

    It's important that if your discovery is to have "real world" (as in commercial/industrial) applications, it needs to be cost-effective (either it saves money spent on existing processes or generates a profit from new processes). In fact, INEEL materials scientist Daniel Branagan is quoted as saying that the research team "purposely used off-the shelf technology to apply the coatings with the idea of increasing the ease of getting this technology out to industry".

    P.S. - The article is quoted as saying that it's one of the hardest metallic materials known so any comparisons to diamond are not really applicable given that diamond is actually an allotrope of Carbon, which is a non-metal. Furthermore, while diamond is a strict, tetrahedral crystalline structure, the Super Hard Steel is actually a "non-crystalline metallic glass" (meaning that it has no specific structure, although the article mentions that the coating can be heated to create a stable structure made up of small crystals). So in all fairness, the two can't really be properly compared because they're not the same types of material.

    • The technology doesn't actually have to be super-competitive at first in order to have long-run potential. In fact, if it uses a lot of off-the-shelf processes, that may actually limit its potential for reducing costs later. Here's why:

      a) Most fabulous, new technologies are more expensive than the competing technologies when they are first introduced. But after a few generations of production, costs come down into the competitive range. Formally speaking, this is because most new technologies are governed by a "learning curve" or "experience curve." Every time you double the amount of the new thing that you've produced, you cut costs by a fixed percentage (e.g., 20%). New technologies can overtake old technologies in price, because output of a brand-new technology can grow exponentially, producing linear drops in price, while the established industries are stuck at more-or-less linear growth levels, yielding only logarithmic(?) drops in price.

      b) The learning curve effect is most pronounced when you don't use off-the-shelf technology in your innovation. You can get the cost of the first generation down quite a bit by using a lot of off-the-shelf components, but then there's nowhere to go from there -- the prices are already set for all your components and they're not falling. On the other hand, if your new technology uses a lot of customized processes or materials, you can get rapid drops in price as you boost output -- every successive generation is a chance to improve your customized approaches.

      Computers are a good example of the learning curve effect (and I bet you'll find that Moore's law only holds true as long as you have exponential growth in output). Wind and solar energy technology also show huge learning effects, while coal and gas plants don't, so there's hope for us yet.

      The one caveat here is that output of a new technology may grow quite slowly at first if it isn't competitive for many applications when it is first introduced (although every new technology is competive for some applications). So progress down the learning curve may be slow early on, if you start with very high costs. But once your prices come down a little and you start competing in more applications, your costs can start falling really fast if there are learning curves at work. On the other hand, if your technology is based entirely on off-the-shelf components, you'll be stuck where you started.

  • The process they describe seems to prohibit the use of the super hardened metal to all but the super high funded projects. Maybe the Space Cable? Alumunum used to be wicked expensive many many years ago until they found a way to simplify the manufacturing process turning it into the cheap disposable metal it is today.
    • If that were the case the cost of recycling it would have to be less the cost of mining and refining the bauxite, which it is not. The cost of recycling Aluminum is about 1/20 the cost of producing 'new' metal from bauxite. Thus making it the most cost effective household material for recycling. Also, since savings is in reduced use of electricity, it benefits everyone who has to purchase electricity off the grid to recycle their aluminum.

      Annually, the aluminum industry saves enough electricity by recycling to reduce by 60 the overall need for power plants in the US.

      • You're thinking about aluminum production after the discovery of the electrical refinement process. Before this was developed, the metal was extremely expensive, more expensive than gold on an ounce-by-once basis.

        Since that new refining technique has been developed nobody thinks twice about tossing out an item containing pounds of aluminum. Recycling it would be nice, of course, but nobody is going into bankruptcy if they toss out old lawn furniture or the like. Try doing that with an equivalent amount of gold!

        It's interesting to note that a similar change may be pending with another metal - I can't remember if it's titanium or platinum. Today the metal is still very expensive, but in a few years it may be as affordable as aluminum today.

        • by PD ( 9577 )
          Those metals have something else that makes them expensive: machining. They are hard metals, and it costs a lot of money to make something out of them. Of course, if we have cheap super hard steel, then we can make machine tools out of it, and cutting titanium won't be any problem. Then, you get to figure out how to make welding titanium cheap and easy.

          I think right now, I'd love to see someone make a good turbopump out of this super hard steel. But with our luck, the inventor is probably thinking about frying pans and rakes.

    • What are you basing this on? The article explicitly contradicts what you're saying:

      From the beginning, Branagan's goal was to develop a coating that would have real-world applicability. "We purposely used off-the shelf technology to apply the coatings with the idea of increasing the ease of getting this technology out to industry," Branagan said.

      Oh yeah, and:

      The product is also extremely affordable because it is only a steel which has exotic structures. It costs only a fraction of what hard ceramics such as tungsten carbide.

      So I'm pretty optimistic about this process. The only potential difficulty I see is the environment needed to apply the coating -- high pressure, high velocity, high temperature. It could be that the combination of these may rule out some applications, but I guess that since we're talking about steel anyway most manufacturing processes should be able to withstand those conditions.

  • OLD News (Score:3, Funny)

    by Strange Ranger ( 454494 ) on Thursday August 09, 2001 @11:44AM (#2151416)
    KITT's [teamknightrider.com] had this technology [teamknightrider.com] since the 80's.

    Figures, Devon got screwed at Patent Office.
    • Here's a nice quote from that KITT page you linked to:

      "You'd need a structure the size of a truck to hold a computer large enough to make the decisions K.I.T.T. makes while auto-cruising down the block."

      Right. Because we all know that when it comes to building computers, it's all about the physical size of the hardware. A computer the size of a car couldn't possibly do it, but one the size of a truck--no problem.
  • by 11223 ( 201561 ) on Thursday August 09, 2001 @11:43AM (#2151592)
    Transparent aluminum!
  • of the molecular spray used as a perminant coating in L. Ron Hubbards Battelfield Earth. Suppose the Church of Scientology will claime prior art?

    Disclamer: Yes, I know he started Scientology, but I read it when I was a kid before I even knew what Scientology was.

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