New material gives copper superalloy-like strength
news.lehigh.edu
news.lehigh.edu
It's a copper-tantalum-lithium alloy: 96.5% Cu, 3% Ta, 0.5% Li.
Tantalum isn't soluble in copper and doesn't form any intermetallic compounds, so under normal circumstances you'd get something like a metal matrix composite -- pure tantalum particles dispersed in a copper matrix. Add lithium, though, and the intermetallic Cu3Li forms, and tantalum is apparently very attracted to this stuff, so you end up with Cu3Li particles with Ta shells in that copper matrix.
Yield Strength = ~1000MPa, so it's genuinely on par with high-temp nickel superalloys, though somewhat weaker than the cobalt-base ones, and far weaker than the best steels.
Interestingly, it's actually a little bit weaker than the copper-beryllium alloy C17200. (YS: ~1200-1300 MPa.) But CuBe is very expensive, not very ductile, and potentially hazardous. Tantalum, though expensive, is still 10x cheaper than beryllium.
Depending on its thermal and electrical properties, and on its ease of manufacture, this could be a very versatile material, and may replace nickel/cobalt alloys in certain applications.
Even firearm suppressors, high voltage electrical parts (especially in specific areas in ultra high power motors and switch contactors), etc.
Special steels can also cost a fortune (powder metallurgy, superduplex).
There are many more foundries and workshops producing copper alloys than nickel alloys. The supply chain is much simpler and more diverse.
Copper recycling is a reality, but nickel alloy recycling is less so. Significant efforts are being made to reduce dependence on rare metals. No one really knows which ones will actually break through in the future. But having more options is always a good thing.
Googled it and the Cobolt Institute says:
> the vast majority is produced as a by-product from large scale copper and nickel mines
And to state the obvious, just because cobalt is usually a byproduct of copper mining, doesn't mean that copper mining usually produces cobalt as a byproduct.
However I found a news article from about 18 months ago stating Rio Tinto, who apparently own that mine, signed an MOU with another company to explore recovering cobalt and bismuth, by experimenting on this mine. Which I take to mean is possible but not being done at present.
But in a January update they mention bismuth experiments but not cobalt: https://www.fortuneminerals.com/news/press-releases/press-re...
Typical rebar is 500MPa or higher.
https://reid.com.au/upload/modules/document_loader/ReidBar_D...
I was thinking structural steel as in that used for columns and beams etc.
Example material test certificate for typical plate used for laser cutting structural steel bolted connection cleats welded to main member hot rolled steel structural sections, which are made from very similar bulk steel:
https://cdn.dcs.bluescope.com.au/download/a-guide-to-using-t...
There may be unstable hydrodynamic phenomena in a pipe or heat exchanger, which generates a large number of thermal cycles. Such as the instability of a vortex in a mixing or heat exchange zone.
This is a different ageing mechanism. It is very complicated and time-consuming to test in the laboratory.
By the ITER design they use beryllium to multiply neutrons to make their supply of Helium 3.
Also https://en.wikipedia.org/wiki/Berylliosis does not sound fun.
I'm also not sure how much being in an alloy would impact the antimicrobial effects of copper.
Generally copper does retain its antibacterial properties in alloys where it's a high proportion of the alloy, like this one.
Tantalum is in demand today, yes. Tantalum capacitors are a well known application, but it is used in all sorts of things.
My point was that even if tantalum were free, a material that is 96.5% copper is still not going to be significantly cheaper than copper, which I think is a pretty self-evident outcome.
There’s a reason that people tin-plate the food-contact surfaces of copper cookware.
I do in fact have some brass and alpaca "silverware". Because of the nickel, the alpaca stuff doesn't corrode; the brass stuff does, and if I don't keep the corrosion scrubbed off with steel wool, not only does it look like shit, acidic foods like yogurt taste bad. But I haven't gotten sick from it. It's probably not impossible to get sick that way, but it's challenging because of the short contact time, the low temperature, the small contact area, and the nasty taste.
Boiling tomato sauce down in a copper pot for a couple of hours is a different situation, and I wonder if this may have contributed to the early modern belief that tomatoes were poisonous. But the toxicity of copper acetate from vinegar (verdigris, used as a pigment) was already well-known.
Unplated copper pots have been commonplace for centuries and in use for millennia, and the most common way to get poisoned by them is to neglect to scrub off the blue-green basic copper carbonate that forms eventually from exposing wet copper to air. The carbonate is enormously more reactive to acids than the bare metal. My father-in-law related an incident from his childhood where a girl in his village got in a lot of trouble by poisoning half the village by cooking in unscrubbed copper!
Nobody died, though. Heavy metal poisoning from copper is not the same kind of menace as lead, arsenic, cadmium, and mercury. We can tolerate much higher levels, and it doesn't bioaccumulate.
Sounds impossible if you don't realize the horseshoes weren't steel.
The others I'm not so sure about. I think you'd have corrosion issues with water tanks and bacterial issues there are easily addressed by regulating temperature. And why would heat exchangers require particularly high strength? Since when are those a structural component?
In any case as you said electroplating something cheap is probably the way to go.
As for water tanks, regulating temperature is not always "easy", and a major reason copper is used for water pipes is its great resistance to corrosion. In this case apparently it will be more expensive than the same mass of stainless, but it's apparently also stronger than stainless, so maybe you can use less of it, making it cheaper again.
The heat exchanger point is interesting. However doesn't stainless already lose out to 3D printed aluminum for the sort of applications where the optimization is worth the cost? This material is even heaver than steel and substantially more expensive.
It's tangential but I wonder how amenable to 3D printing this material will prove to be.
High-energy cryogenic ball milling of 10 grams for four hours in a continuous flow of liquid nitrogen under an argon atmosphere with <1ppm oxygen (https://www.science.org/action/downloadSupplement?doi=10.112...) sounds expensive, but maybe they only did it that way because it was a low-risk way to ensure the alloying worked with the lab equipment they had on hand, not because it's the cheapest way to make the material. Hopefully cheaper ways are found.
I'm no expert in heat exchangers, but my calculations suggest 3-D printing is or will be an enormous boost there, and may reverse the gradient of merit for wall material thermal conductivity, favoring good thermal insulators over good thermal conductors like copper and aluminum. As for aluminum, it is only suitable for low temperatures.
I'm curious. What mechanism would lead to an insulator being favored in a heat exchanger?
Fair point about aluminum and temperature. As a layman an engine block is high temperature to me. I guess this would be extremely useful for more exotic stuff.
I could be wrong about this, but I didn't just make it up; I got it from Lingai Luo's book on heat and mass transfer intensification, which hopefully I've understood correctly.
With 3D printing I wonder if you could insert bands of insulator into an otherwise conductive wall? But you're dealing with large (potentially ridiculously so) temperature ranges so I wonder if it would prove difficult to match the thermal properties of the two materials closely enough.
I now have the weirdest desire to play with heat exchanger designs that I have absolutely zero use for. I've been nerd sniped.
When we’re talking about advanced materials, "high strength" means hundreds of MPa and "high temperature" is beyond 500°C (and more depending on the application).
(It would be excellent to be able to clean my silverware by firing it in a kiln, though with a copper alloy I'd probably have to scrub off the verdigris.)
Ok but if you do that then what is the point of the exercise? I thought fancy flatware was thin because of the appearance. If the edges are thick doesn't that defeat the purpose?
The equivalent thickness being something like 5x stronger is of course the benefit here.
I don't think price is an issue for high end home use items. Rich people buy far weirder and more expensive things.
Price is always an issue. Maybe you're willing to pay €100 a spoon, or €1000, or even €10000, but nobody is going to pay €1000000000 per spoon. If there's a good chance the price will drop by a factor of 10 in the next year, many rich people might be unwilling to pay even €100.
The process described sounds like it would currently be able to produce a spoon for a cost on the order of €100k: four PhDs working for a month is maybe €50k, but they're also tying up a lot of rather expensive lab space, and I think they're using analytical-grade fine chemicals rather than metallurgical-grade copper and tantalum. And in this study they made roughly enough for half a spoon. The second spoon would probably cost closer to €1000.
In an adjacent exchange it seemed we both expected the price to be far lower. 10x or even 50x the material cost of a piece of stainless steel flatware seems well within budget for a rich customer.
And I found some studies suggesting that 304 and 316 stainless steel leach very little nickel when in contact with food. It’s the cheaper nickel-containing stainless steel that’s a problem.
But even if suitable - it will be mostly novelty I guess. Still want one.
This new alloy is useful only for high-temperature applications, like turbines and heat exchangers, where its main advantage over the existing alloys (based on nickel or cobalt) is its much higher thermal conductivity.
Moreover, the kinds of stainless steel that have little or no nickel content (e.g. ferritic, martensitic, superferritic, duplex, manganese-austenitic) will always have a price several times lower than any copper alloy.
This copper alloy will be rather expensive due to the high cost of tantalum. However the content in tantalum is small, so the price will remain acceptable for its applications.
Iron ore costs $~100/ton, The cost of copper ore is hard to find (possibly because there are so many types, and because it tends to be processed locally AFAICT) but you're looking at ~$5000/ton.
So the raw-material cost should be about 50x, and apparently stainless steel costs ~$2500/ton so even if the processing is free you're already 2x the price.
So, no. Copper is about as rare as lithium, for context. Iron is an amazingly cheap metal.
And it's clear the article's author doesn't understand scientific writing. Each participant is identified as having a PhD (when true), contrary to accepted academic practice. Imagine a scientific article by Albert Einstein, tagged with "PhD" -- except that in 1905, any relevance aside, Einstein didn't have one. My point is that the participants' academic degrees are irrelevant to the science. As Richard Feynman said, "Science is the organized skepticism in the reliability of expert opinion". Oh -- wait -- did I mention that Feynman had a PhD?
My favorite phrase from an article that tries to raise empty PR prose to an art form: "... Lehigh is the only university in the Lehigh Valley to have this designation ..." Noted. But this is like saying, "We're tops in our ZIP code!"
https://en.wikipedia.org/wiki/Aluminium-conductor_steel-rein...
Aluminum is a worse conductor than copper on a volumetric basis but a better conductor on a mass basis, which is important for overhead lines supporting their own weight against gravity. It also costs significantly less than copper.
Nuclear plants?
Maybe useful in supercomputing/quantum computing?
"Nuclear plants?"
Sure. One of the most challenging problems in a PWRs is heat exchange; the so called "steam generators" that circulate primary and secondary water, for instance. They're huge, expensive heat exchangers and their primary failure mode is cracking. A durable, high temperature, high thermal conductivity copper based alloy goes directly to this. Better thermal conductivity could make these devices substantially smaller, reducing costs in all sorts of way, or enable novel designs.
The design of these alloys and exchangers is extremely complex and benefits from several thousand years of operational experience. This applies to the alloys themselves, their heat treatment, shaping, interaction with other materials, ageing, etc.
It is highly unlikely that these alloys will be abandoned in the next 20-30 years.
Then presently coal plants are less flexible with throttling with their output compared with natural gas. The new alloy may level the field and make coal plants to fit better with renewables.
I was wondering if some naturally occurring copper ores could give a hardness advantage over pure copper, before the true copper-tin Bronze Age kicked off.
I doubt it beats aluminium in cost, so it would need to significantly beat carbon in performance to make it worthwhile.
The advantages of this alloy do not make it a better choice than special steels or titanium alloys when it comes to metallic materials.
There are few cyclists on Venus.
"""
Unlike typical grain boundaries that migrate over time at high temperatures, this complexion acts as a structural stabilizer, maintaining the nanocrystalline structure, preventing grain growth and dramatically improving high-temperature performance.
The alloy holds its shape under extreme, long-term thermal exposure and mechanical stress, resisting deformation even near its melting point, noted Patrick Cantwell, a research scientist at Lehigh University and co-author of the study.
"""
This sounds exotic, but possibly better performing in some use cases?
And the intro numbers are... Exciting.
> This core-shell structure neither dissolves nor coarsens at temperatures of up to 800°C while also causing the yielding strength to be in excess of 1 gigapascal.
Imagine cutting stainless steel with a copper-based blade, and not the other way around.