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Scientists Identify Possible New Substance With Highest Melting Point

Posted by Soulskill on from the new-hotness dept.

JoshuaZ writes: Researchers from Brown University have tentatively identified an alloy of hafnium, nitrogen and carbon as having an expected melting point of about 7,460 degrees Fahrenheit (4120 Celsius). This exceeds that of the previous record-breaker, tantalum hafnium carbide, which melts at 7,128 F (3942 C). Its record stood for almost a century. At this point, the new alloy is still hypothetical, based on simulations, so the new record has not yet been confirmed by experiment. The study was published in Physical Review B (abstract), and a lay-summary is available at the Washington Post. If the simulations turn out to be correct, the new alloy may be useful in parts like jet engines, and the door will be opened to using similar simulations to search for substances with even higher melting points or with other exotic properties.

3 of 92 comments (clear)

  1. Probably not useful by dj245 · · Score: 5, Informative

    If the simulations turn out to be correct, the new alloy may be useful in parts like jet engines, and the door will be opened to using similar simulations to search for substances with even higher melting points or with other exotic properties.

    No, it won't. Materials for jet engines must be reasonably affordable, machinable or otherwise workable, and available in large quantities. I have about 4600 lbs [2086kg] of 422 stainless going through my shop right now for a single row of blades for one machine. They're big blades, but even for small blades, hundreds of pounds of material is common. An alloy of hafnium, nitrogen and carbon isn't going to be cheap enough for that to ever be feasible. It is probably a brittle material as well. Brittle materials and a high vibration environment don't mix.

    Maybe you could apply it as a coating, but I'm not sure how that would be possible. Almost all coatings of this type require you to liquify or vaporize the coating material. Plus, you run into the same problem as before- a thin coating won't protect the base metal, and a thick one would be prohibitively expensive.

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    Even those who arrange and design shrubberies are under considerable economic stress at this period in history.
    1. Re:Probably not useful by EmperorArthur · · Score: 5, Informative

      Hafnium is about a dollar / gram. Nitrogen and carbon are plentiful and relatively cheap. Is this dramatically more expensive than current high temp materials?

      442 stainless steel is US $1500.00 / Ton from Alibaba. Assuming metric, that works out to $1.5/kg, or $0.0015/g.
      Plus that $1/g is just for the raw Hafnium. Alloys like the one proposed here tend to be expensive, time consuming, and finicky to get right.

      Then you get into the fact that producing Hafnium leaves pure Zirconium. Which is typically used as cladding for nuclear fuel rods. Something that a fair portion of the world would freak out about, because anything that's good for nuclear must be bad. Plus there's this gem: https://en.wikipedia.org/wiki/...

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      So lets pretend that we've just completed writing this code, as opposed to having just completed sabotaging it -Altera
    2. Re:Probably not useful by Anonymous Coward · · Score: 2, Informative

      Most current single crystal alloy development is focused on the elimination of Hf because of cost and difficulty in maintaining consistent supply. The other very expensive raw material we use is Platinum for oxidation/corrosion coatings. There's also significant focus into reducing and eliminating platinum use. Pratt & Whitney got away from Platinum coating years ago. GE and Rolls still use a lot of platinum but are working on reducing the amount.

      Raw material cost is a significant part of gas turbine airfoil part cost.