11 ms·

An alloy of iron and aluminium is as good as titanium, at a tenth of the cost

258 points by RachelF 12y ago

VBprogrammer 12y ago
'As good as' is a silly phrase to use in metallurgy. Are we talking machinability, castability, tensile strength or hardness. Not to mention less obvious issues like food safety or resistance to corrosion? There are very many alloys of both aluminium and steel all of which have there uses. To say this one is as good as titanium means very little.
- teh_klev 12y ago
  And if you read to the end of the article it does have the caveat: "There is, of course, many a slip ’twixt laboratory bench and production line"
- maxerickson 12y ago
  The linked abstract is somewhat clearer: http://www.nature.com/nature/journal/v518/n7537/full/nature14144.html http://www.nature.com/nature/journal/v518/n7537/full/nature1... The specific tensile strength and ductility of the developed steel improve on those of the lightest and strongest metallic materials known, titanium alloys So presumably it is stronger and somewhat more workable than titanium.
- dredmorbius 12y ago
  From TFA: "Dr Kim has produced a material which has the strength and the lightness of titanium alloys but will, when produced at scale, cost a tenth as much."
- gooseyard 12y ago
  flavor
- chromaton 12y ago
  Then there's yield strength, ultimate strength, magnetic properties, heat/cold compatibility, toughness, ductility, density, weldability, modulus of elasticity and aesthetics.
- SapphireSun 12y ago
  Don't forget bioactivity / toxicity ;) Ti implants are popular because of the metal's low bioactivity amongst other desirable properties.
trhway 12y ago
>By manipulating the structure of steel on a nanometre scale, Dr Kim has produced a material which has the strength and the lightness of titanium alloys but will, when produced at scale, cost a tenth as much. i wonder what if the same to be applied to titanium. >Steel is useful because it is strong and cheap. But it is also heavy. It has, therefore, always been useless for applications such as aircraft. http://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-25 http://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-25 "The MiG-25 was constructed from 80% nickel steel alloy, 11% aluminium, and 9% titanium."
- fleitz 12y ago
  "It turned out that the weight of the aircraft necessitated large wings."
  - dexen 12y ago
    > "It turned out that the weight of the aircraft necessitated large wings." As opposed to other combat aircrafts featuring large wings for high-altitude performance and maneuverability. Before we diss steel as viable aircraft material, note that weight was increased both by heavy engines† and presumeably heavy avionics, as those were based on vacuum tubes. Including a 600kW (!) radar, if we are to quote Wikipedia everywhere. † the engines alone, at 4900kg a pair are 25% of MiG's dry weight, add some overhead for support structures necessited by their sheer power. For contrast, F/A-18's engines are 20% of dry weight.
    - Shivetya 12y ago
      plus last I read it wasn't designed to dogfight but to chase down proposed mach 3 bombers the US was building; XB-70 and such
  - trhway 12y ago
    of course. At those speeds you don't have much choice of materials - basically either steel or titanium - and that choice results in the huge difference in weight and thus in range. Compare MiG-25 with Blackbird: " On the SR-71, titanium was used for 85% of the structure, with much of the rest polymer composite materials." But you just can't build your interceptor/fighter force out of titanium - it is extremely cost prohibitive. The point here is that steel is pretty legitimate aircraft material in specific part of the performance/cost envelope.
nakedrobot2 12y ago
Not a moment too soon for the Tall Tower Project. http://hieroglyph.asu.edu/project/the-tall-tower/ http://hieroglyph.asu.edu/project/the-tall-tower/
- davidw 12y ago
  I bought that book and was kind of disappointed - the stories are pretty hit and miss. I did like that particular story though.
  - DennisP 12y ago
    I felt the same way, but for me the story about the solar brick-making robots made the whole thing worthwhile.
- luke_s 12y ago
  While it's undoubtedly very cool to build something very, very ... very, very tall, what would such a tower be used for?
  - amelius 12y ago
    to cast a shadow over the rest of town :)
  - onion2k 12y ago
    What's the Eiffel Tower for? The Statue of Liberty? Nelson's Column? The St. Louis Gateway Arch? They're symbols. They bring people together around a common talking point, to recognise and remember who we are and what we can do together. If it really needs a purpose the Very Tall Tower could be an awesome base-jumping venue.
  - tryeng 12y ago
    Base jumping!
jcrei 12y ago
Made me think of Rearden metal from Atlas Shrugged
- joakleaf 12y ago
  Yes, me too. As I recall, Rearden metal was about 10x as strong as the competitors'. I guess Rearden was based on real life Andrew Carnegie who helped ignite the use of steel for construction (http://en.wikipedia.org/wiki/Andrew_Carnegie http://en.wikipedia.org/wiki/Andrew_Carnegie). I assume Ayn Rand based all her characters on former industry giants (railroads, steel, oil).
  - shiven 12y ago
    One can only imagine the fun she would have had with a main character based on Steve Jobs or Jeff Bezos!
    - csours 12y ago
      Don't know why you are being downvoted, these guys are notable for being perceived as not giving fig for what other people thought, and being successful doing it.
gaius 12y ago
This, if it works, is worth quite literally millions as times as much as another "social network" or stupid app, but I'll wager the team aren't "acqui-hired" for $19Bn.
- louhike 12y ago
  I do not think you can make the comparison. The article is about a science paper, and you are talking about the company Whatsapp. Facebook had already explained why they bought it at this cost. The kind of Titanium here (Ti6Alv4V) does not seem to be that good, so "it seems" we should not be too optimistic here (but I'm just a developer, correct me if I'm wrong).
- ghshephard 12y ago
  I'm interested in where you came up with the "literal" worth comparison. Perhaps what you meant to say is that, "I personally feel that this new steel alloy is worth more than whatsapp, and, I would be personally prepared to pay at a valuation of 1 million times greater than the whatsappp valuation. So, going back in time, if I had a choice of owning 10% of whatsapp for a $10,000 investment (valuing whatsapp at $100K), or 0.00001% of the company producing this alloy (valuing it at $100B, or 1 million times as much as whatsapp, I would take the 0.00001% for my $10,000 instead of the 10% share of whatsapp for $10,000). Is that literally how you feel?
  - anon1385 12y ago
    Congratulations, you illustrated his point beautifully.
  - omega_rythm 12y ago
    Welcome to this year edition of the Galactic HyperBowl. Whether from the mountains of Deneb Drei, Vega Primo red glow, Jupi II clouds or the Green Fields of Durulis, don't miss the titans of the HNFL fighting for the most coveted sport trophy of the universe (Special discount for believers of the Chutch of TFA). Access available to Lusus game fields — this year hosting planet — from the WorldWeb (free FarCasting for Gold Card owners), or full immersion SensoDive(tm) to experience the game As-If-You-Were-There. Contact our representatives for exclusive access to (TC secured) transmission feeds.
ohitsdom 12y ago
Every year I am reading these kinds of articles, keep thinking we are going to have amazing materials in 5 years.
- DennisP 12y ago
  This one has a major steel company planning to start production in one year.
upofadown 12y ago
With aircraft the basic issue is strength to weight, not just weight. If the material is stronger you can use less of it. The trend today is to make aircraft out of really strong fibres embedded in plastic.
- Tuna-Fish 12y ago
  The new material has the strength to weight of titanium.
  - tsotha 12y ago
    Titanium is no better than aluminum. The reason they use titanium in aircraft is its ability to withstand heat.
wycx 12y ago
Now that nature lets you read articles for free you can actually go and read the original paper. In the paper the authors had to heat treat the steel at 900 °C for 15 mins to generate the microstructure that gave the properties they wanted. So, what does welding do to the microstructure? Does this material need to be heat treated again at 900 °C after welding? Does the the hard-but-brittle B2 intermetallic reform in the HAZ?
- TheCraiggers 12y ago
  Interesting question, although I'm not sure it applies much in the real world. Aren't the welds themselves typically the weakest link in a build? Seems like the engineering tricks used to keep welds under stress from ripping apart would also benefit the affected metal in the HAZ.
  - chromaton 12y ago
    Welds can be stronger than the HAZ. See this video from Lincoln Electric on welding chrome-moly: http://youtu.be/W5dVAT9PTmw?t=7m53s http://youtu.be/W5dVAT9PTmw?t=7m53s
    - djcapelis 12y ago
      Yep! Generally if your weld breaks before the material in the HAZ it is considered a bad weld and certified welders working under structural standards are generally required to produce welds that are stronger than this. (Not actually a certified welder right now, but I have a brief familiarity with the D1 structural standards as getting a cert is something I've looked into.)
- rsfern 12y ago
  That's a really interesting question, and I'm not sure what the answer should be. According to the authors, the B2 intermetallic forms in small particles during recrystallization at 900 C because of the influence of the nickel, so you might expect a similar high rate of particle nucleation in the wake of the melt pool, resulting in small, dispersed particles. Then again, you might get coarse intermetallic phases instead, resulting in a brittle weld. In either case, the advantage of the B2 particles is that they allow a high degree of strengthening during work hardening, which would be done before welding. Any subsequent heat treatment would tend to undo that work hardening.
daniel-levin 12y ago
Since the original paper is behind a paywall (at least for me), can anyone explain the specifics of what the researchers did to produce this new alloy? >> Dr Kim and his colleagues have, however, found that a fifth ingredient, nickel, overcomes this problem. I'd imagine that it didn't take a world-class team of scientists to have come up with the idea of alloying using nickel. There is no way materials scientists and metallurgists hadn't tried this by now, so what did they do differently?
- cataphract 12y ago
  Since this is mostly undecipherable for me, I'll just quote: «A common method of uniformly distributing fine particles in a matrix is to make the best use of highly potent nucleation sites for inducing the precipitation of the particles. In this study, potential nucleation sites for B2 during annealing of wrought sheet steel include (1) grain boundaries or edges of recrystallized austenite crystals and (2) deformation shear bands, which are common in hot- or cold-worked low-density steel. To expand the stability domain of B2 above the recrystallization temperature (normally, 800–900 °C) of deformed austenite, the alloying recipe of an austenitic low-density steel was modified by adding 5 weight per cent nickel (Ni), which is one of the most effective elements for forming B2 with aluminium. The addition of Ni to low-density steel may appear to conflict with the collective wisdom of ferrous alloy design; Ni has been regarded merely as a well-known austenite stabilizer like Mn and C; and Ni has been little noticed in low-density steel design, mainly because it is not a critical determinant of the density in ferrous alloys.» (citations omitted)
- rsfern 12y ago
  Materials Science PhD student here, I'll do my best. The morphology of the brittle B2-FeAl intermetallic compound is the key. In the conventional lightweight steel alloys, the B2 intermetallics make the alloy brittle (so they don't work harden very well), so in the past researchers optimized their alloys to avoid forming these intermetallics [0]. The nickel promotes the nucleation of the intermetallic particles during heat treatment [1], so that you get a more-or-less uniform distribution of many nanocrystalline B2 particles, instead of a smaller number of larger or more clustered B2 domains. The small B2 particles contribute to strain hardening by pinning dislocation motion, without reducing the ductility of the alloy. From the Nature letter: [0]: "One of the general concepts employed until now in the alloy design of Fe-Al-Mn-C-based, high-aluminium, low-density steel has been the suppression of ‘brittle’ intermetallic compound formation by stabilizing the ‘ductile’ austenite matrix." [1]: "To expand the stability domain of B2 above the recrystallization temperature (normally, 800–900 °C) of deformed austenite, the alloying recipe of an austenitic low-density steel was modified by adding 5 weight per cent nickel (Ni), which is one of the most effective elements for forming B2 with aluminium."
damoncali 12y ago
Cool, but I wonder about stiffness. When I was an aero engineer, we tended to use aluminum because most of our designs were limited by stiffness, not strength. Since aluminum is lighter than either steel or titanium, you can take advantage of geometry (which greatly impacts stiffness) without sacrificing weight. Strength was only rarely the bottleneck. Interestingly, the stiffness to weight ratio of aluminum, steel and titanium are all approximately equal. We did occasionally use titanium, but usually some sort of steel was a better choice when strength was the issue. It's just the way it works out. It's also worth noting that for the work I did, cost was never an issue (NASA) - material costs were basically insignificant. We could use whatever we wanted.
- jfoutz 12y ago
  You have way more insight than I do. What you describe reminds me of a complicated webbing of aluminum to hold everything in place. If I understand you correctly having access to a titanium equivalent could do two things. One, you could reduce part count, replace an array of aluminum supports with one titanium part. If the strength and weight are about the same, the simpler design seems better to me. Two, you could free up some space for other stuff. I'm thinking fuel tanks in wings, but i'm not even at the level of armchair aerospace engineer. There are probably many cases where aluminum is lighter but bulkier. Opening up a channel to simplify wiring, or hydraulics could be helpful.
  - damoncali 12y ago
    The trouble is that it's not a lot of space, and it's not as simple as stiffness/weight of the material. Think about something simple like a structural tube. The diameter of the tube has significantly more impact on it's stiffness than it's material. So if you use a 30% lighter, but strong enough material, you can add 30% to the cross sectional area of the tube- which means you can make it a bit bigger in diameter, which will have potentially huge impacts on overall structural stiffness. Note that adding 30% more material will add at least 30% more strength to the part (huge oversimplification here, but just for arguments sake, we'll use that simple tensile case). Titanium was useful when we needed very high strength on a very large part - a good example is the trunnions that attach payloads to the space shuttle cargo bay. These are large metal bars a little over 3 inches in diameter and maybe a couple feet in length. Aluminum is not strong enough. Steel would be punishingly heavy. (do the math - these things are beasts). So titanium can be a good fit for stuff like that. But most steel parts were small - things like bolts, rod ends an the like. They tend to be specialized with very specific detailed requirements for things like fatigue, frictional characteristics, and that sort of thing. Because they are small, the weight just isn't that big an issue. Bigger stuff was almost always aluminum, which is actually a lot stronger than most folks realize. At least, the good stuff is. Titanium also has some other odd properties that make it troublesome in space. I wasn't a materials guy, but they were always bitching about "hydrogen embrittlement" and the fact that large titanium parts do not burn up on re-entry like aluminum does, which presents a debris hazard to people on the ground. (I don't know how big a problem that really is, but people didn't want to be dumping space junk on top of people's heads. Honestly, I just took this on faith - people were concerned about it, but it always struck me as odd.)
phkahler 12y ago
So the steel companies are finally getting scared enough to innovate. There are people trying to dramatically reduce the cost of titanium, Ford is dumping steel for aluminum, composites are even replacing aluminum in aircraft. Steel is starting to look like a relic of the 1700's rather than the great material it has been for so long. When I worked in EVs, one of the old timers (a guy almost 80 years old) told me the best steel for the motors should have some Boron in it. Some particular alloy that would have lower core loss at higher frequencies. But none of the big steel companies were interested in making it for us. They just wanted to make what they make. So even if it's not as great as it sounds, I'm glad somebody is doing something with steel.
- Gravityloss 12y ago
  There are lots of steel factories around the world. Some smaller ones have specialized in rarer steels.
  - bigger_cheese 12y ago
    As a materials engineer who works for a steel company (although my background is in blast furnaces and iron ore smelting - not micro alloying) maybe I can shed some light. It largely comes down to enconomies of scale you can certainly make specialised grades of steel but often times it is not profitable to do so. Steelmaking is like most manufacturing process, cost decreases with scale. Usually the specialised grades simply aren't in high enough demand to recoup the costs involved in producing them. For some grades the techniques to produce them are suitably differnt from standard grades that lines needs to be diverted and retooled to handle them, which impacts on yield and causes losses due to downtime etc. Not to mention many of the specialised alloying elements like Niobium etc. are also stupidly expensive. Buying these in small quanities is probably not ideal and I'd imagine its probably risky to buy in bulk because orders may not be filled quickly and business doesn't tend to like having capital tied up in raw material stockpiles. Competition is also very fierce, for a while there has been an excess of steel capacity largely driven by rapid expansion of China's steelmaking capacity. So there is a lot of pressure on keeping operating costs per tonne low all of this kind of leads companies towards where the biggest returns are, which is producing the high volume steels at lowest cost. Thus most of research effort gets directed here as well. Thats not to say R&D isn't happening into specialised grades, its just not where the big payoffs are currently.
chromaton 12y ago
Has anyone tried a titanium-iron-nickel alloy? I would have thought every alloy combination would have been tried by now, but I guess there's still new things to be learned.
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ris 12y ago
Which is all great but as far as I'm aware one of the major reasons for titanium's use was its high melting point. Nothing is said of how this compares here.
Animats 12y ago
It will be good if this is real. Nature articles about nanotechnology which claim "huge breakthrough to be commercialized real soon now" are all too frequent. Then we never hear about the technology again. For aerospace, the big advantage of titanium is a high melting point. This material won't have that, which is probably why the authors talk about automotive applications. For automotive applications, a question is whether these new properties will survive ordinary manufacturing processes. Casting, probably not, but maybe the process can be applied to castings later as a heat-treating step. What about rolling and stamping?
- rsfern 12y ago
  In the original article they say they cold-roll, recrystallize, then strain harden. So definitely no casting, because the recrystallization is where the magic happens. Rolling and casting should be fine though. They say that the alloy is mostly compatible with current steel processing infrastructure, so it looks promising.
dschiptsov 12y ago
Rearden metal?)
alricb 12y ago
Some data: The yield strength of that new material is from about 1 GPa to 1.4 GPa, vs. 830 MPa for Ti6Al4V (Steel and Aluminium vary, depending on the alloy). It has a density of 6.82 g/cm3, vs 4.43 for the titanium alloy, 7.85 for ordinary steel or 2.70 for 6061 Aluminium. Apparently Ti6Al4V costs around $20/kg, so the new alloy would cost around $2/kg, vs. around $2.70/kg for 6061 Aluminium or $0.85/kg for cold-rolled steel. Prices: http://www.metalprices.com/metal/steel/steelbenchmarker-cold-rolled-coil-usa http://www.metalprices.com/metal/steel/steelbenchmarker-cold... http://www.metalprices.com/metal/aluminum/aluminum-6061-extrusion-billet-price http://www.metalprices.com/metal/aluminum/aluminum-6061-extr... http://www.metalprices.com/metal/titanium/titanium-ingot-6al-4v-usa http://www.metalprices.com/metal/titanium/titanium-ingot-6al... As for the modulus of elasticity, it isn't mentioned in the article. The usual figure for steel is 210 GPa. The titanium alloy is around 114 GPa, and 6061 Aluminium is 69 GPa. The low density is fairly big new. Compared to mild steel, you can have a 15% larger volume for the same weight, so you might be ahead on stiffness even if the MoE is smaller.
tsotha 12y ago
>An alloy of iron, aluminium and carbon (steel’s other essential ingredient) is too brittle to be useful. Adding manganese helps a bit, but not enough for aluminium-steel to be used in vehicles. >Dr Kim and his colleagues have, however, found that a fifth ingredient, nickel, overcomes this problem. As far as I know turbine blades are typically made of iron-nickel alloys. What is the new part of this discovery?

258 points by RachelF 12y ago

'As good as' is a silly phrase to use in metallurgy. Are we talking machinability, castability, tensile strength or hardness. Not to mention less obvious issues like food safety or resistance to corrosion? There are very many alloys of both aluminium and steel all of which have there uses. To say this one is as good as titanium means very little.

teh_klev 12y ago
And if you read to the end of the article it does have the caveat: "There is, of course, many a slip ’twixt laboratory bench and production line"
maxerickson 12y ago
The linked abstract is somewhat clearer: http://www.nature.com/nature/journal/v518/n7537/full/nature14144.html http://www.nature.com/nature/journal/v518/n7537/full/nature1... The specific tensile strength and ductility of the developed steel improve on those of the lightest and strongest metallic materials known, titanium alloys So presumably it is stronger and somewhat more workable than titanium.
dredmorbius 12y ago
From TFA: "Dr Kim has produced a material which has the strength and the lightness of titanium alloys but will, when produced at scale, cost a tenth as much."
gooseyard 12y ago
flavor
chromaton 12y ago
Then there's yield strength, ultimate strength, magnetic properties, heat/cold compatibility, toughness, ductility, density, weldability, modulus of elasticity and aesthetics.
SapphireSun 12y ago
Don't forget bioactivity / toxicity ;) Ti implants are popular because of the metal's low bioactivity amongst other desirable properties.

trhway 12y ago

>By manipulating the structure of steel on a nanometre scale, Dr Kim has produced a material which has the strength and the lightness of titanium alloys but will, when produced at scale, cost a tenth as much. i wonder what if the same to be applied to titanium. >Steel is useful because it is strong and cheap. But it is also heavy. It has, therefore, always been useless for applications such as aircraft. http://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-25 http://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-25 "The MiG-25 was constructed from 80% nickel steel alloy, 11% aluminium, and 9% titanium."

fleitz 12y ago
"It turned out that the weight of the aircraft necessitated large wings."
- dexen 12y ago
  > "It turned out that the weight of the aircraft necessitated large wings." As opposed to other combat aircrafts featuring large wings for high-altitude performance and maneuverability. Before we diss steel as viable aircraft material, note that weight was increased both by heavy engines† and presumeably heavy avionics, as those were based on vacuum tubes. Including a 600kW (!) radar, if we are to quote Wikipedia everywhere. † the engines alone, at 4900kg a pair are 25% of MiG's dry weight, add some overhead for support structures necessited by their sheer power. For contrast, F/A-18's engines are 20% of dry weight.
  - Shivetya 12y ago
    plus last I read it wasn't designed to dogfight but to chase down proposed mach 3 bombers the US was building; XB-70 and such
- trhway 12y ago
  of course. At those speeds you don't have much choice of materials - basically either steel or titanium - and that choice results in the huge difference in weight and thus in range. Compare MiG-25 with Blackbird: " On the SR-71, titanium was used for 85% of the structure, with much of the rest polymer composite materials." But you just can't build your interceptor/fighter force out of titanium - it is extremely cost prohibitive. The point here is that steel is pretty legitimate aircraft material in specific part of the performance/cost envelope.

nakedrobot2 12y ago

Not a moment too soon for the Tall Tower Project. http://hieroglyph.asu.edu/project/the-tall-tower/ http://hieroglyph.asu.edu/project/the-tall-tower/

davidw 12y ago
I bought that book and was kind of disappointed - the stories are pretty hit and miss. I did like that particular story though.
- DennisP 12y ago
  I felt the same way, but for me the story about the solar brick-making robots made the whole thing worthwhile.
luke_s 12y ago
While it's undoubtedly very cool to build something very, very ... very, very tall, what would such a tower be used for?
- amelius 12y ago
  to cast a shadow over the rest of town :)
- onion2k 12y ago
  What's the Eiffel Tower for? The Statue of Liberty? Nelson's Column? The St. Louis Gateway Arch? They're symbols. They bring people together around a common talking point, to recognise and remember who we are and what we can do together. If it really needs a purpose the Very Tall Tower could be an awesome base-jumping venue.
- tryeng 12y ago
  Base jumping!

jcrei 12y ago

Made me think of Rearden metal from Atlas Shrugged

joakleaf 12y ago
Yes, me too. As I recall, Rearden metal was about 10x as strong as the competitors'. I guess Rearden was based on real life Andrew Carnegie who helped ignite the use of steel for construction (http://en.wikipedia.org/wiki/Andrew_Carnegie http://en.wikipedia.org/wiki/Andrew_Carnegie). I assume Ayn Rand based all her characters on former industry giants (railroads, steel, oil).
- shiven 12y ago
  One can only imagine the fun she would have had with a main character based on Steve Jobs or Jeff Bezos!
  - csours 12y ago
    Don't know why you are being downvoted, these guys are notable for being perceived as not giving fig for what other people thought, and being successful doing it.

gaius 12y ago

This, if it works, is worth quite literally millions as times as much as another "social network" or stupid app, but I'll wager the team aren't "acqui-hired" for $19Bn.

louhike 12y ago
I do not think you can make the comparison. The article is about a science paper, and you are talking about the company Whatsapp. Facebook had already explained why they bought it at this cost. The kind of Titanium here (Ti6Alv4V) does not seem to be that good, so "it seems" we should not be too optimistic here (but I'm just a developer, correct me if I'm wrong).
ghshephard 12y ago
I'm interested in where you came up with the "literal" worth comparison. Perhaps what you meant to say is that, "I personally feel that this new steel alloy is worth more than whatsapp, and, I would be personally prepared to pay at a valuation of 1 million times greater than the whatsappp valuation. So, going back in time, if I had a choice of owning 10% of whatsapp for a $10,000 investment (valuing whatsapp at $100K), or 0.00001% of the company producing this alloy (valuing it at $100B, or 1 million times as much as whatsapp, I would take the 0.00001% for my $10,000 instead of the 10% share of whatsapp for $10,000). Is that literally how you feel?
- anon1385 12y ago
  Congratulations, you illustrated his point beautifully.
- omega_rythm 12y ago
  Welcome to this year edition of the Galactic HyperBowl. Whether from the mountains of Deneb Drei, Vega Primo red glow, Jupi II clouds or the Green Fields of Durulis, don't miss the titans of the HNFL fighting for the most coveted sport trophy of the universe (Special discount for believers of the Chutch of TFA). Access available to Lusus game fields — this year hosting planet — from the WorldWeb (free FarCasting for Gold Card owners), or full immersion SensoDive(tm) to experience the game As-If-You-Were-There. Contact our representatives for exclusive access to (TC secured) transmission feeds.

ohitsdom 12y ago

Every year I am reading these kinds of articles, keep thinking we are going to have amazing materials in 5 years.

DennisP 12y ago
This one has a major steel company planning to start production in one year.

upofadown 12y ago

With aircraft the basic issue is strength to weight, not just weight. If the material is stronger you can use less of it. The trend today is to make aircraft out of really strong fibres embedded in plastic.

Tuna-Fish 12y ago
The new material has the strength to weight of titanium.
- tsotha 12y ago
  Titanium is no better than aluminum. The reason they use titanium in aircraft is its ability to withstand heat.

wycx 12y ago

Now that nature lets you read articles for free you can actually go and read the original paper. In the paper the authors had to heat treat the steel at 900 °C for 15 mins to generate the microstructure that gave the properties they wanted. So, what does welding do to the microstructure? Does this material need to be heat treated again at 900 °C after welding? Does the the hard-but-brittle B2 intermetallic reform in the HAZ?

TheCraiggers 12y ago
Interesting question, although I'm not sure it applies much in the real world. Aren't the welds themselves typically the weakest link in a build? Seems like the engineering tricks used to keep welds under stress from ripping apart would also benefit the affected metal in the HAZ.
- chromaton 12y ago
  Welds can be stronger than the HAZ. See this video from Lincoln Electric on welding chrome-moly: http://youtu.be/W5dVAT9PTmw?t=7m53s http://youtu.be/W5dVAT9PTmw?t=7m53s
  - djcapelis 12y ago
    Yep! Generally if your weld breaks before the material in the HAZ it is considered a bad weld and certified welders working under structural standards are generally required to produce welds that are stronger than this. (Not actually a certified welder right now, but I have a brief familiarity with the D1 structural standards as getting a cert is something I've looked into.)
rsfern 12y ago
That's a really interesting question, and I'm not sure what the answer should be. According to the authors, the B2 intermetallic forms in small particles during recrystallization at 900 C because of the influence of the nickel, so you might expect a similar high rate of particle nucleation in the wake of the melt pool, resulting in small, dispersed particles. Then again, you might get coarse intermetallic phases instead, resulting in a brittle weld. In either case, the advantage of the B2 particles is that they allow a high degree of strengthening during work hardening, which would be done before welding. Any subsequent heat treatment would tend to undo that work hardening.

daniel-levin 12y ago

Since the original paper is behind a paywall (at least for me), can anyone explain the specifics of what the researchers did to produce this new alloy? >> Dr Kim and his colleagues have, however, found that a fifth ingredient, nickel, overcomes this problem. I'd imagine that it didn't take a world-class team of scientists to have come up with the idea of alloying using nickel. There is no way materials scientists and metallurgists hadn't tried this by now, so what did they do differently?

cataphract 12y ago
Since this is mostly undecipherable for me, I'll just quote: «A common method of uniformly distributing fine particles in a matrix is to make the best use of highly potent nucleation sites for inducing the precipitation of the particles. In this study, potential nucleation sites for B2 during annealing of wrought sheet steel include (1) grain boundaries or edges of recrystallized austenite crystals and (2) deformation shear bands, which are common in hot- or cold-worked low-density steel. To expand the stability domain of B2 above the recrystallization temperature (normally, 800–900 °C) of deformed austenite, the alloying recipe of an austenitic low-density steel was modified by adding 5 weight per cent nickel (Ni), which is one of the most effective elements for forming B2 with aluminium. The addition of Ni to low-density steel may appear to conflict with the collective wisdom of ferrous alloy design; Ni has been regarded merely as a well-known austenite stabilizer like Mn and C; and Ni has been little noticed in low-density steel design, mainly because it is not a critical determinant of the density in ferrous alloys.» (citations omitted)
rsfern 12y ago
Materials Science PhD student here, I'll do my best. The morphology of the brittle B2-FeAl intermetallic compound is the key. In the conventional lightweight steel alloys, the B2 intermetallics make the alloy brittle (so they don't work harden very well), so in the past researchers optimized their alloys to avoid forming these intermetallics [0]. The nickel promotes the nucleation of the intermetallic particles during heat treatment [1], so that you get a more-or-less uniform distribution of many nanocrystalline B2 particles, instead of a smaller number of larger or more clustered B2 domains. The small B2 particles contribute to strain hardening by pinning dislocation motion, without reducing the ductility of the alloy. From the Nature letter: [0]: "One of the general concepts employed until now in the alloy design of Fe-Al-Mn-C-based, high-aluminium, low-density steel has been the suppression of ‘brittle’ intermetallic compound formation by stabilizing the ‘ductile’ austenite matrix." [1]: "To expand the stability domain of B2 above the recrystallization temperature (normally, 800–900 °C) of deformed austenite, the alloying recipe of an austenitic low-density steel was modified by adding 5 weight per cent nickel (Ni), which is one of the most effective elements for forming B2 with aluminium."

damoncali 12y ago

Cool, but I wonder about stiffness. When I was an aero engineer, we tended to use aluminum because most of our designs were limited by stiffness, not strength. Since aluminum is lighter than either steel or titanium, you can take advantage of geometry (which greatly impacts stiffness) without sacrificing weight. Strength was only rarely the bottleneck. Interestingly, the stiffness to weight ratio of aluminum, steel and titanium are all approximately equal. We did occasionally use titanium, but usually some sort of steel was a better choice when strength was the issue. It's just the way it works out. It's also worth noting that for the work I did, cost was never an issue (NASA) - material costs were basically insignificant. We could use whatever we wanted.

jfoutz 12y ago
You have way more insight than I do. What you describe reminds me of a complicated webbing of aluminum to hold everything in place. If I understand you correctly having access to a titanium equivalent could do two things. One, you could reduce part count, replace an array of aluminum supports with one titanium part. If the strength and weight are about the same, the simpler design seems better to me. Two, you could free up some space for other stuff. I'm thinking fuel tanks in wings, but i'm not even at the level of armchair aerospace engineer. There are probably many cases where aluminum is lighter but bulkier. Opening up a channel to simplify wiring, or hydraulics could be helpful.
- damoncali 12y ago
  The trouble is that it's not a lot of space, and it's not as simple as stiffness/weight of the material. Think about something simple like a structural tube. The diameter of the tube has significantly more impact on it's stiffness than it's material. So if you use a 30% lighter, but strong enough material, you can add 30% to the cross sectional area of the tube- which means you can make it a bit bigger in diameter, which will have potentially huge impacts on overall structural stiffness. Note that adding 30% more material will add at least 30% more strength to the part (huge oversimplification here, but just for arguments sake, we'll use that simple tensile case). Titanium was useful when we needed very high strength on a very large part - a good example is the trunnions that attach payloads to the space shuttle cargo bay. These are large metal bars a little over 3 inches in diameter and maybe a couple feet in length. Aluminum is not strong enough. Steel would be punishingly heavy. (do the math - these things are beasts). So titanium can be a good fit for stuff like that. But most steel parts were small - things like bolts, rod ends an the like. They tend to be specialized with very specific detailed requirements for things like fatigue, frictional characteristics, and that sort of thing. Because they are small, the weight just isn't that big an issue. Bigger stuff was almost always aluminum, which is actually a lot stronger than most folks realize. At least, the good stuff is. Titanium also has some other odd properties that make it troublesome in space. I wasn't a materials guy, but they were always bitching about "hydrogen embrittlement" and the fact that large titanium parts do not burn up on re-entry like aluminum does, which presents a debris hazard to people on the ground. (I don't know how big a problem that really is, but people didn't want to be dumping space junk on top of people's heads. Honestly, I just took this on faith - people were concerned about it, but it always struck me as odd.)

phkahler 12y ago

So the steel companies are finally getting scared enough to innovate. There are people trying to dramatically reduce the cost of titanium, Ford is dumping steel for aluminum, composites are even replacing aluminum in aircraft. Steel is starting to look like a relic of the 1700's rather than the great material it has been for so long. When I worked in EVs, one of the old timers (a guy almost 80 years old) told me the best steel for the motors should have some Boron in it. Some particular alloy that would have lower core loss at higher frequencies. But none of the big steel companies were interested in making it for us. They just wanted to make what they make. So even if it's not as great as it sounds, I'm glad somebody is doing something with steel.

Gravityloss 12y ago
There are lots of steel factories around the world. Some smaller ones have specialized in rarer steels.
- bigger_cheese 12y ago
  As a materials engineer who works for a steel company (although my background is in blast furnaces and iron ore smelting - not micro alloying) maybe I can shed some light. It largely comes down to enconomies of scale you can certainly make specialised grades of steel but often times it is not profitable to do so. Steelmaking is like most manufacturing process, cost decreases with scale. Usually the specialised grades simply aren't in high enough demand to recoup the costs involved in producing them. For some grades the techniques to produce them are suitably differnt from standard grades that lines needs to be diverted and retooled to handle them, which impacts on yield and causes losses due to downtime etc. Not to mention many of the specialised alloying elements like Niobium etc. are also stupidly expensive. Buying these in small quanities is probably not ideal and I'd imagine its probably risky to buy in bulk because orders may not be filled quickly and business doesn't tend to like having capital tied up in raw material stockpiles. Competition is also very fierce, for a while there has been an excess of steel capacity largely driven by rapid expansion of China's steelmaking capacity. So there is a lot of pressure on keeping operating costs per tonne low all of this kind of leads companies towards where the biggest returns are, which is producing the high volume steels at lowest cost. Thus most of research effort gets directed here as well. Thats not to say R&D isn't happening into specialised grades, its just not where the big payoffs are currently.

chromaton 12y ago

Has anyone tried a titanium-iron-nickel alloy? I would have thought every alloy combination would have been tried by now, but I guess there's still new things to be learned.

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ris 12y ago

Which is all great but as far as I'm aware one of the major reasons for titanium's use was its high melting point. Nothing is said of how this compares here.

Animats 12y ago

It will be good if this is real. Nature articles about nanotechnology which claim "huge breakthrough to be commercialized real soon now" are all too frequent. Then we never hear about the technology again. For aerospace, the big advantage of titanium is a high melting point. This material won't have that, which is probably why the authors talk about automotive applications. For automotive applications, a question is whether these new properties will survive ordinary manufacturing processes. Casting, probably not, but maybe the process can be applied to castings later as a heat-treating step. What about rolling and stamping?

rsfern 12y ago
In the original article they say they cold-roll, recrystallize, then strain harden. So definitely no casting, because the recrystallization is where the magic happens. Rolling and casting should be fine though. They say that the alloy is mostly compatible with current steel processing infrastructure, so it looks promising.

dschiptsov 12y ago

Rearden metal?)

alricb 12y ago

Some data: The yield strength of that new material is from about 1 GPa to 1.4 GPa, vs. 830 MPa for Ti6Al4V (Steel and Aluminium vary, depending on the alloy). It has a density of 6.82 g/cm3, vs 4.43 for the titanium alloy, 7.85 for ordinary steel or 2.70 for 6061 Aluminium. Apparently Ti6Al4V costs around $20/kg, so the new alloy would cost around $2/kg, vs. around $2.70/kg for 6061 Aluminium or $0.85/kg for cold-rolled steel. Prices: http://www.metalprices.com/metal/steel/steelbenchmarker-cold-rolled-coil-usa http://www.metalprices.com/metal/steel/steelbenchmarker-cold... http://www.metalprices.com/metal/aluminum/aluminum-6061-extrusion-billet-price http://www.metalprices.com/metal/aluminum/aluminum-6061-extr... http://www.metalprices.com/metal/titanium/titanium-ingot-6al-4v-usa http://www.metalprices.com/metal/titanium/titanium-ingot-6al... As for the modulus of elasticity, it isn't mentioned in the article. The usual figure for steel is 210 GPa. The titanium alloy is around 114 GPa, and 6061 Aluminium is 69 GPa. The low density is fairly big new. Compared to mild steel, you can have a 15% larger volume for the same weight, so you might be ahead on stiffness even if the MoE is smaller.

tsotha 12y ago

>An alloy of iron, aluminium and carbon (steel’s other essential ingredient) is too brittle to be useful. Adding manganese helps a bit, but not enough for aluminium-steel to be used in vehicles. >Dr Kim and his colleagues have, however, found that a fifth ingredient, nickel, overcomes this problem. As far as I know turbine blades are typically made of iron-nickel alloys. What is the new part of this discovery?