Hm I just read an article here recently that was saying that Americans had an edge in jet turbine blades production over china because Americans figured out how to make single crystal jet turbines using this same method. I wonder what the difference is.
This is really cool metallurgy. They start with an alloy and deform it and because of elemental size mismatch they can cause the alloy to self assemble into nanoscale crystals with three different structures
As an aside, “super alloy” is not the best wording choice on the part of the author of this sciencealert article, superalloys are an established alloy family that follow a different design strategy and have a very different composition profile https://en.wikipedia.org/wiki/Superalloy
I guess I'm not impressed that some totally different alloy is stronger than steel. You can't change both method and alloy and claim that the method is better. Presumably the paper compared the same alloy using the normal and the new method, but this article omitted that essential information, and in so doing destroyed the result.
And as a personal exercise in intellectual humility, I cast my eyes over the supplementary materials (as those are free-to-the-public)… I’d recommend it:
I get a huge thrill out of looking at serious work outside my expertise. When I’m tempted to imagine the proposition is as simple as it seems from the headline (or the article, or the editor’s note, or the abstract), it excites me to remember just how deeply and carefully and thoroughly people think through things I barely understand.
Presumably, some initial information was fed into the start of this reporting process. Multiple stages of this process had near-total incomprehension of the information yet performed full ingestion and reconstitution of it anyway, leading to this terminally-confused output.
The science daily article is just incorrect to call this a superalloy, which it is not. This is a high entropy refractory alloy (HfNbTaTiZr), superalloys are usually based on lighter metals and they usually have only one dominant element while HEAs have 4+ dominant elements
Interesting for products where the resulting alloy just needs machining - lathing, milling, drilling etc, but more interesting will be what processes will be needed to weld or form such alloyed metals.
Existing high-strength alloys like MP35N are already extraordinarily difficult to machine. The "super alloy" in the story is said to have a compressive yield strength of 2 gigapascals, which is about MP35N tensile yield. Sounds like this "super alloy" isn't that much stronger than existing high strength alloys. It does have some fairly exotic alloying elements, tantalum, niobium and hafnium that probably don't come cheap. This super alloy will be used only in a very few applications.
I have not struck MP35N afaik before, and interesting to see its use in commercial settings, and even available as bolts and nuts. Certainly not fun to machine [1]
It's hard to know just how much stronger this new processing of the alloy is than other common high strength alloys, as they list compressive yield and not tensile yield strength ... that's if the person writing didn't get the two terms confused.
As a note, I use duckduckgo and smirked somewhat at its search assist results for the few efforts to find the compressive yield of Bisalloy 400 (something I've had to drill) - checking out the listed sources it was clear it had mistakenly used the tensile yield ...
As an illustration for the differences, I found a page [2] for 4140 alloy and similar yield strengths. 4140 is reasonably workable, drilling isn't the greatest amount of effort either before it's tempered and annealed.
The paper: https://www.science.org/doi/10.1126/science.aec4995
As an aside, “super alloy” is not the best wording choice on the part of the author of this sciencealert article, superalloys are an established alloy family that follow a different design strategy and have a very different composition profile https://en.wikipedia.org/wiki/Superalloy
> It's two times stronger than steel, three times stronger than aluminum, and twice as strong as the same alloy made in a conventional way.
The source paper in Science, fwiw:
https://www.science.org/doi/10.1126/science.aec4995
And as a personal exercise in intellectual humility, I cast my eyes over the supplementary materials (as those are free-to-the-public)… I’d recommend it:
https://www.science.org/doi/suppl/10.1126/science.aec4995/su...
I get a huge thrill out of looking at serious work outside my expertise. When I’m tempted to imagine the proposition is as simple as it seems from the headline (or the article, or the editor’s note, or the abstract), it excites me to remember just how deeply and carefully and thoroughly people think through things I barely understand.
https://phdcomics.com/comics/archive.php?comicid=1174
It's hard to know just how much stronger this new processing of the alloy is than other common high strength alloys, as they list compressive yield and not tensile yield strength ... that's if the person writing didn't get the two terms confused.
As a note, I use duckduckgo and smirked somewhat at its search assist results for the few efforts to find the compressive yield of Bisalloy 400 (something I've had to drill) - checking out the listed sources it was clear it had mistakenly used the tensile yield ...
As an illustration for the differences, I found a page [2] for 4140 alloy and similar yield strengths. 4140 is reasonably workable, drilling isn't the greatest amount of effort either before it's tempered and annealed.
[1] https://www.practicalmachinist.com/forum/threads/milling-mp3...
[2] https://amesweb.info/Materials/Steel-Tensile-Yield-Strength-...
https://en.wikipedia.org/wiki/Mazinger_Z
https://en.wikipedia.org/wiki/Chogokin