Metal Alloys of the Future? 

Rad, thanks for the extra insight! Just gonna pin your comment to the top for the time being, seems easier than rephrasing into an addendum of corrections :) Taking a look at "A critical review of high entropy alloys and related concepts" now, cheers for the tip!

the definition of HEA is a big debate indeed, I believe the name is too simplistic :) To my understanding, HEA = a single solid solution, since the configurational entropy (which is only one contribution for the total entropy) is supposed to stabilise it; in the end, the choice of metals is quite limited to suit this definition, you maybe have an handful of systems that fulfil it. But if you design an multi-element alloy with multiple phases, then it would be best suited to call it chemical complex alloy or something similar. This field is really interesting!

@@loicp.1487 HEAs don't actually have that much mixing entropy. For an equiatomic alloy of N components, you get a molar mixing entropy of S = R * ln(N) where R is ideal gas constant. (you can do the rearrangement of terms in the proof from statmech en.wikipedia.org/wiki/Entropy_of_mixing) Natural log is not a fast growing function. Because of this, many people working in the field, including me, prefer the term 'multi-principal metal alloy' . They still have many excited properties, but the mixing entropies are not one of them.

@@BreakingTaps I wish I had known you were making this video, HEAs/MPEAs are my major focus now. You could have picked my brain or I could have connected you with a more hands-on expert. That said, if you are working on a corrosion video in the future, I could connect you with some experts that love telling stories.

@@MichaelWatersJ maybe I was not clear enough, sorry… I was trying to make a difference between HEAs and CCAs/MPMAs. My point was, if you go back to the early Yeh’s papers, he clearly states that the mixing entropy is the reason of the existence of such solid solutions. It has been demonstrated otherwise since (not every combination of 5 elements gives a solid solution), and I am aware there are tons of metallic alloys that exhibit higher values of entropy than HEAs. Sorry if my message was source of misunderstanding

Perhaps something akin to electrostatic attraction could allow for thin films of different metals to be sprayed and wiped off in thin layers. Then, take your thin cake of metals, and crush it like damascus.

It might be harder with metals with dramatically different galvanic potentials, where the easier to reduce salts would act like a sacrificial anode on a ship in reverse and precipitate first.

@@forresthsu582 true, but if a solution was reducing enough it might minimize that issue. Starting with metals that have very similar electrochemical potentials would be a good place to start tho. There are some insanely reducing chemicals out there tho and it would be fun to try to get this to work with very weird mixtures of metals

@@doctorpurple5173 or borrow CERN for about a million hours...

@@CharlieLOL that sounds easier, I'll go ahead and do that

Does high entropy tend to imply high energetic cost? The enthalpy part makes me think yes. This is a science language trick. We've always known that a good Smith makes magic metal given a long enough time with enough fuel in a hot enough furnace. That's always been the case.

Cool.

Do you think exposing the particles to a strong magnetic field while "forging" would have an effect?

@@thebogsofmordor7356 possibly yes. In my considerations, I've sought to eliminate as many engineering complications as possible, applying such a field within a furnace introduces quite a few difficulties; melt times would have to be 4-6 hours minimum I think to maximize chances of success. Another point of consideration is how you cool it (quickly to the lowest solidifying temp of the constituent elements and then gradually to room temp over 2-3 hours is my idea in order to maximize homogenous crystal formation although there are a few different permutations of procedures that would likely need experimented with before success) during which applying static and alternating fields (electric and magnetic) could produce beneficial effects and would be much easier from an engineering standpoint.

@@thebogsofmordor7356 dunno, but would be a great experiment !

Mhm the idea isn't bad but you would need singel atom metal dust to generate a HEA also forget the heating over the liquidus that would lead to phase separation like we have seen in the first nano droplets BT has shown us and it is absolutely unnecessary ever heard of coold welding just bring the metal atoms near enough together and they will share there electrons aka bind together now you say and why don't stick 2 metal pieces together if they touch well at first the oxide layer that is a spacer between also even if same atoms get to bind the strength that holds the pieces together is not even noticeable by hand and a not perfect surface will only make it worse But I know 2 cases of coold welding high precision meesurment blocks (they ar so smooth that they stick together by the atmosphere and if not seperated after use the trapped air in between the surfaces will escape and well Invar is an 2/3 iron 1/3 nickel alloy so double the Ni containt of stainless Steel just leaking Chrome you can imagine the basically non existing oxide layer And the second is/are stainless steel bolds and nuts they cann weld together after tighting the stainless prevents oxides from forming and the pressure with the movement against each other ripping up the old oxid layer and making them fiz

For sure! One of my ancestors was ate by one.

Woo hoo! I'm gonna go find me some mermaids! Someone get King Ferdinand II on the phone!

**later that day** "Dude this king guy is an IDIOT! Killer party bro! This is the life! Jessica bring me some more white pixie dust! Weeeeheeeewww!*" *lower lip curled american hollering.

Yep, we gleaned that from the commentary.

@A channel “largely unexplored” is complete nonsense. We’ve explored and mapped most of the ocean and it’s floors. It’s mostly empty waters.

Imagine the crazy materials we could make if we could choose exactly what atoms went on every space on the cube

Not to mention programmable alloy volumes.

In theory if you have really good control over the sputtering process, you're approaching something similar to Atomic Layer Deposition or Molecular Beam Epitaxy! Can basically lay down precise layers of atoms and build the crystal from the ground up. I think that still tends to give you a layered alloy so it'll be slightly different than a more amorphous sample derived from something like an arc furnace or laser. But could be a really useful starting material, i.e. take that and anneal it to let the atoms shift around some.

@@BreakingTaps Ah yes, I wondered if something like annealing would cause useful amounts of diffusion too. I guess it depends on how long you hold the sample at the high temperature in an inert atmosphere or vacuum?

@@BreakingTaps Can you have multiple sputter targets at the same time?... Multiple beams at the same molecular transfer rate could create a near perfect mix on the substrate.

In my adolescent mind I don't like to embarrass myself, but I can't help it, but what is the difference between the lasers you are using as compared to the plasma furnace that is supposed be a major change economically from the electrode furnaces now in commercial use. Is it possible for deposited material to be proactively different than a concentration of energy of the laser? Fascinating stuff even for a dullard like myself, keep it coming, even Goodyear stumbled across something novel while cluelessly experimenting.

bismuth alloys would be a good candidate

♥ Hi hi! I was sorta hoping you had a bunch of crystal and metallurgy corrections that I could pin to the video 😂 Yeah not sure about the adhesion issue, if it would be desirable for the film to stick better or not. Or if it would even matter... the laser process is pretty aggressive and might do the same everytime regardless. Dunno! Probably the right thing to do is to blap it all off the slide into solution, then repeatedly irradiate the solution itself (focal point in the middle of the vial) to re-process the flakes and particles. The "igital alloying idea is definitely doable although falls in "really annoying" category :) I've been looking into it because I want to play with nanolaminates of alternating layers. You can define sputter sequences to run automatically and the machine seems to use a simple XML file to define those sequences, so I think I can create a long sequence and import it to run. The major issue is that it only has two sputter heads, so if I wanted 121212 it's easy but 123123 would require cycling the chamber and waiting for it to pump back down (solid hour or two for the oxidation-sensitive metals). (I'm working on a pulsed laser deposition setup with the new vac chamber, might be easier with that system. Not as nice of layers, but easier to deposit many different materials at once) But on that note, would it be possible to anneal thin layers into an alloy? Say deposit alternating layers that are only 1-2nm thick, stack up 50-100nm of layers and then anneal it all together. Would the metal have enough mobility at temperature to reconfigure into a crystal, or is that just a recipe for everyone separating out into distinct phases?

Dave H I was going to say that adhesion to glass will be better if the first layer is Cr or Ti. The layer can be very thin. I don't know how well Ni would work.

I mean, your "almost nothing" is probably considerably more than the majority of the comments on here tryharding to sound knowledgeable. xD Also, I love how I can hear your voice in your writing.

@@BreakingTaps Have you tried to use laser deposition to deposit all five elements at once? It seems like that would make a High Entropy metal alloy layer.

@@BreakingTaps "would it be possible to anneal thin layers into an alloy?" It's something smiths have to watch out for when making a pattern welded (damascus) billet. Too many folds & too much heat gives you an ugly mottled alloy blade instead of a beautiful weld pattern.

Guess thinking about it like a spring is mayby a solution... It's hard steel but can spring

@@africanelectron751 mayby

Nobody expects the Spanish Inquisition. Good luck. 👍

Ah neat! I didn't realize there was such a range of interpretation about how these are defined. I did see a few alternate naming schemes (multiple-component alloy and the like) but didn't realize it was more than just a naming thing. Very cool, thanks for sharing the extra details!

Spread the word, that's how we can help as this is very helpful to many. Totally agree : )

Haha yeah, I bet they make quite a racket!

Can confirm, we wear plugs and muffs while running ours.

rapid cooling should produce good glass with very high entropy; why do you think otherwise?

​@@janami-dharmam High entropy alloys have crystalline structures, typically BCC or FCC or the mixture of these. The thing that you are talking about is metallic glasses (or amorphous alloys). They do not have a periodic crystal structure. Metallic glasses and HEAs are two different things, however, sometimes people refer to MGs as the predecessors of HEAs.

Funny you mention this...in the early 2010s when bulk metallic glass research started to fizzle out (outside of magnetics) a lot of metallic glass researchers shuffled over into HEA research.

Haha, yeah, the descriptions here about HEA's (or whatever we're calling them) reminded me of some of the interest we had around amorphous metals. One of my colleagues was looking at a family of alloys when I finished my M.S. in 2008. Wonder what came of it. I know corrosion resistance (crack propagation) was a big motivation.

We've had real floating (through magnetic repulsion+attraction that quantum locks it in place just like superconductors but stabilized in a different manner than the effect that locks superconductors to magnets) hoverboards for almost a decade now. They'll always require a ferromagnetic material to stand on, (or an impossibly diamagnetic material which can't physically exist afaik) so it's as real as it gets already

I was wondering this too. Would it be possible to have multiple sputtering heads in a large chamber pointing in the same direction so you get mixing in the plasma phase?

Yep! But with a caveat. Metals sputter at different rates, even if they are alloyed together. So the mixture that lands on the substrate is often different than the mixture in the sputtering target. But otherwise it's definitely possible. Can also mix "in the chamber" as @seeigecannon suggested, or do things like introduce process gasses to react with the plasma in-flight (typically used to make oxides).

@@BreakingTaps Could you also magnetically trap the particles and stir them together before depositing them? I'm thinking of inductive levitating metals, where you have two opposing yoke coils made up of a single wire, preferably insulated, and one could pulse it to "trap" and then dump the mixture onto the surface.

@@BreakingTaps Could you make your own sputter target with five different segments? You could size them inversely to their sputtering rate.

I need to get my head out of the internet.

Whoops! You're right :)

I suspect that could work! Would be hard to generate a lot of material, this laser process struggles to make even micrograms of material. But if you had enough of the individual nanoparticles you could probably mix them together either with the laser itself, or with something like an arc furnace.

I work in a production job and there IS a process we use. And having been iq tested several times and knowing where i stand amongst people percentile-wise, i was given a laugh at your comment about your frustrations. Not one of derision at all. But i watch people all day try to performatively bypass the process (which isnt perfect by the way but is established and was done so by lots of people who are fairly switched on and have been focused on the primary priorities) to serve one part of a complex goal or their own fancy. I had a unit come to me today for testing. I had rejected it yesterday to repair for a non conformity. The response of the repair person was a repair on a different nonconformity. I already knew what they had fudged but tested it anyway out of curiosity. The repair guy on my shift comes over and does the equivalent of thumbing the scale to pass it. This is on my name. So i let him. It passed. At which point he buzzed off amd i retested it checking the original noncom and the part of the scale he thumbed. As it happens it still passed. And it truly passed. Theres only so many ways to fake my guage or externally fool it. I wansnt doing them and since they dont require the more definitive test either on the client side or the provider side, it passed. Theres no established way for me to test this, even though that's the end customer use case. But, it would have been faster just to change the noncom part. And it would have better served quality to send the whole unit back to reprocess. But it passed. All that being said i like the way you think because you at least understand that it would have been better to do what you ougtta. And THAT being said, dont quit that trying to work around bit. It is how better methods are made. As long as its tempered by ethics.

@@metamorphicorder May you find Jesus

@@metamorphicorder well your high iq ... i presume high but lol, may want to edit your grammer before posting... just saying if your going to exclaim your brilliance perhaps an edit is in order. Lmfao

@@metamorphicorder To be fair, you have to have a very high IQ to understand intermetallics. And yes, by the way, i DO have a high entropy alloy tattoo. And no, you cannot see it. It's for the ladies' eyes only- and even then they have to demonstrate that they're within 5 IQ points of my own (preferably lower) beforehand. Nothin personnel kid 😎

@@Jefferson-ly5qe what the actual fuck are you talking about?

Yeah that was a bit of a miss on my part. I had originally wanted to talk about those and binary eutectics like Pb-Sn (or even how most stainless alloys are a bit different since some of the components are interstitial)... but I forgot 😅 Perhaps in a future video! And tbh, I have some more reading to do on my side, some of these concepts are still fuzzy to me and not sure I could explain them coherently yet!

@@BreakingTaps I didn't even think about stainless, 18-8 is less than 75% iron. Also, I've read the word plenty, but I still don't really understand what a eutectic mix is. I know it applies to more than just metals.

Haha yunno I haven't seen it yet, but I wouldn't be surprised either. 😂

Yes, there have been ballistic tests on a number of HEAs. They usually behave like a (very expensive) stainless steel.

I love the idea of an industrial process that includes a tank of mantis shrimp busily punching the materials.

As far as I can tell, it's wide open across most metals and some non-metals! I.e. here's a paper that made DyErGdHoLuScTbY (aip.scitation.org/doi/10.1063/1.5051514). There are quite a few variants out there using refractory metals too, like WNbMoTaV. If I understand correctly, the refractory metals are under a lot of active research right now because they can retain their material properties at very high temperatures, so lots of commercial interest there.

Great idea. I'd be interested to see what some hafnium would produce.

@@WmSrite-pi8ck There are quite a few Hf containing alloys in this space - TiNbHfZr for instance.

...or if not, season lightly with Lanthanides.. ;)

@AlphaPhoenix Not sure if I can even tag other people in a discussion on YT. But he does molecular beam epitaxy IIRC, which would be the way to go for mixing stuff on the atomic level

I was wondering the same.

Thanks! Just on the molecular bio side of things, so not very helpful to the content of the channel. Otherwise just a lot of skimming review articles and watching lectures to get up to speed. All very shallow knowledge though. Mile wide, inch deep sort of thing 😄

Hmm, potentially! With a caveat: metals will sputter at different rates (i.e. silver sputters a lot faster than nickel), so you'd have to do some work to make sure the target sputtered the quantities you wanted. I think something like a checkerboard would work best, otherwise it'll just "eat" through the layers one-by-one and you'll end up with layers on the sample. But in principle something like a checkerboard could work! That's a neat idea, I might see about trying that...

@@BreakingTaps Perhaps the different sputtering rates could be counteracted a bit by strategic layering of the initial layers. So for example if silver sputters faster than nickel then you put silver as the lower layer. Then again I'm not 100% sure of the exact sputtering method.

Please enlighten me, what do isotopes have to do with giving and receiving electrons?

@@baranzenovich It's more that the element atoms have more possible configurations that are stable, which tends to make the element more flexible in terms of giving and receiving electrons from their shell. An isotope of an element has interesting properties, stable isotopes even moreso since they don't experience radioactive decay. An isotope with fewer neutrons has a stronger positive charge, meaning that the electron shell around the atom is more likely to attract any free radicals into its sphere of influence. An isotope with more neutrons has a weaker positive charge which will cause the shell to more willingly cast off electrons to reach stability. In metallurgy, with the formation of crystalline structures as the mixture cools, you'll find that these varied energy states allow the element to more easily 'slot' into place forming a stable alloy instead of beading up and separating. There is a reason why the first alloy that humanity ever mastered was made using copper (a transition metal) as the base and tin (an element with so many stable configurations that it's actually funny). It was an alloy that was ridiculously easy to get right.

@@shadowtheimpure isotopes of an element have fewer / more neutrons, which dont contribute to the positive charge, but the same number of protons, which DO contribute to charge - so i dont think isotopes have a big influence on behaviour in alloys

@@raiyiar doesnt seem outside of the realm of possibility - heavier isotopes of the same element will have greater bond enthalpies due to a lower ZPE. Unsure on the impact of alloys, but in organic chemistry deuterated compounds are incredibly useful for probing reactions for this very reason.

@@benwhitehair5291 well yea, hydrogen has an atomic mass of 1, and deuterium has an atomic mass of 2, so deuterated substances can have sliiightly different behaviour (but i dont think to the extent, that Y-H bonds would be possible in one situation, and Y-D bonds at the same position are impossible) - contrast that with tin, with an atomic mass of around 120 - even if an atom had 10 more neutrons, that would change the atomic mass by less than 10%, which is not nearly as drastic as the doubling with deuterium (or tripling with tritium)

Huh weird, will look into the audio issue. Was recorded at 32bit float, so there must be something in the processing or YT side mucking up the audio. Cheers for the headsup, will investigate!