Podcast: What manufacturers need to know about the shift toward recycled aluminum alloys
Key takeaways
- Solid-phase alloying of aluminum scrap offers a fast, low-cost path to high-strength, recyclable metal products.
- Multi-element alloys from Ames Lab could replace nickel-based superalloys in high-temp turbine applications.
- Real-time molten metal analysis boosts process control, throughput, and product quality in aluminum production.
In this episode of Great Question: A Manufacturing Podcast, Robert Brooks, editor in chief of Foundry Management & Technology and American Machinist, explores three key developments in non-ferrous metallurgy that promise to reshape industrial manufacturing. The discussion highlights breakthrough research from the Pacific Northwest and Ames National Laboratories, including advances in solid-phase alloying of aluminum scrap and the discovery of a new multi-element alloy for high-temperature turbine applications. Robert also examines Arconic’s collaboration with spectroscopy experts to enhance real-time analysis of molten metals. Together, these innovations point to a future where metallurgical progress drives both performance and sustainability across sectors.
Below is an edited excerpt from the podcast:
Hello, and thanks for listening to the Great Question podcast. I'm Robert Brooks with American Machinist and Foundry Management & Technology.
In this installment, I'm going to return to discussing some of the more basic developments shaping manufacturing industries—specifically, metallurgical developments, and even more specifically, non-ferrous metallurgy.
These are some advancements that are well beyond the concept stage and are likely to have an industrial impact in the months to come.
A few weeks ago, I discussed similar developments in iron and steel metallurgy, so this will balance the ledger in some way.
Many listeners know, of course, that the United States has implemented 25% tariffs on imports of semi-finished steel and aluminum. There's some indication that the steel tariffs are affecting foreign and domestic steel production, but the situation in the aluminum supply chain is quite a bit different.
Aluminum has become a significantly important manufacturing material during the past two decades, because it's much lighter than steel but still available at high volumes—and also because it's highly recyclable. So it has become a valuable option for automotive designers and manufacturers, for environmental regulators, and for consumers.
Aluminum was already well established in aerospace design, in construction products, in packaging, in recreation, in transportation, and in several other commercial market segments.
To make a long story short, U.S. manufacturers require a lot of aluminum, and domestic supplies will need to increase in order to avoid significant cost increases when buying aluminum.
A research study published earlier this year by the U.S. Department of Energy’s Pacific Northwest National Laboratory, in a journal called Nature Communications, indicates that aluminum scrap from the industrial waste stream can produce high-performance metal alloys. The aluminum performs comparably with identical materials produced from primary aluminum, indicating that this solid-phase alloying process may be a low-cost route to bring high-quality recycled metal products to the marketplace.
Let me be a little bit discursive here: what's being imported and hit with tariffs is primary aluminum, which is in very short supply. But it's necessary to beef up the total supply, so the ability to recycle more high-quality material will have an impact on the need to pay tariffs on aluminum products.
Of course, the researchers at the Pacific Northwest National Lab are emphasizing the environmental impact as well as the industrial advantages of their development. One of the material scientists there, Mr. Xiao Li—who is also the lead author of the research study—wrote:
"The novelty of our work here is that by adding a precise amount of metal elements into the mix with aluminum chips as a precursor, you can actually transform it from low-cost waste to a high-cost product. We do this in just a single step, where everything is alloyed in five minutes or less."
Their solid-phase alloying process converts aluminum scrap—blended with copper, zinc, and magnesium—into a precisely designed, high-strength aluminum alloy product. Again, in just a few minutes, compared to several days that may be required to produce a similar outcome through conventional melting, casting, extrusion, or other downstream processes.
The research team used a PNNL-patented technique called Shear Assisted Processing and Extrusion—or SHAPE—to achieve their results. But they noted that the findings should be reproducible with other solid-phase manufacturing processes too.
In the SHAPE process, high-speed rotating dies create friction and heat that disperses the coarse starting ingredients into a uniform alloy, with the same characteristics as a newly manufactured aluminum cast or formed product. There is no energy-intensive bulk melting, which is another cost-cutting factor.
Compared to conventional recycled aluminum, the upcycled alloy is 200% stronger and has increased ultimate tensile strength. They write that these characteristics could translate into longer-lasting and better-performing products.
I quote another research scientist there, Cindy Powell:
"Our ability to upcycle scrap is exciting, but the thing that excites me most about this research is that solid-phase alloying is not just limited to aluminum alloys and junk feedstocks. Solid-phase alloying is theoretically applicable to any metal combination you can imagine. And the fact that manufacturing occurs wholly in the solid-state means you can begin to consider totally new alloys that we’ve not been able to make before."
Another metallurgical development involving high-temperature superalloys was reported by the Ames National Laboratory.
Jet engines generate a lot of power—and a lot of heat—so the materials used to form these systems and their component parts are typically nickel- or cobalt-based alloys, called superalloys, which can tolerate temperatures of around 1,000°C or 1,832°F.
Researchers at Ames National Lab in Iowa have discovered a new alloy that can replace nickel- and cobalt-based superalloys in gas turbines, for both aviation and power generation.
They used a computational framework to predict metal phase stability, strength, and ductility based on the types of atoms involved. The framework can very quickly test thousands of material combinations.
The lead research scientist at Ames Lab, Nicholas Argibay, noted that gas turbines are more efficient when they operate at higher temperatures—around 1,400°C or 2,552°F. Given these high operating temperatures, the heat tolerance limits of nickel- and cobalt-based superalloys have been a limiting factor in improving energy efficiency.
Quoting Argibay:
“We currently use cooling and other tricks to try to make those engines run very hot, but ultimately we are limited by the melting temperature of those materials.”
There are about nine elements that melt at much higher temperatures than nickel and cobalt, and those are called refractory metals. The reason we don't use those metals now is because they're brittle at low temperatures, and they're hard to manufacture and shape into parts.
A solution to the challenges posed by refractory metals is to combine them into multi-principal element alloys. Multi-element alloys are not based on one metal that holds everything together, such as a nickel- or cobalt-based alloy. Instead, multi-element alloys consist of three or more elements, none of which exceeds 50% of the overall composition.
The researcher added that combining many of these otherwise pure elements in significant amounts creates atomic structures that he described as “emergent unique properties.”
Determining the materials and the appropriate amounts of each was done using the computational framework developed at Ames Lab by two more research collaborators: Prashant Singh and Dwayne Johnson.
Singh explained that mixing more than three elements results in millions of combinations to search for—which Johnson noted they had addressed using a theory-guided methodology that interfaces with experiments and points them toward new alloys with specific properties they want in their final materials.
This new multi-element alloy approach is more resilient to deformation at high temperatures than the alloys currently in use, which means the material can be exposed to much hotter temperatures—and eliminates the need for cooling the engine, which causes energy loss.
Thanks to its composition, this alloy also has the necessary ductility to make it suitable for manufacturing using commercially established methods.
Finally, Arconic—a company that produces aluminum, titanium, and nickel rolled products, along with engineered components and aluminum forgings for aerospace, automotive, commercial transport, and construction—has engaged spectroscopy specialists to implement real-time molten metal analysis to improve Arconic’s manufacturing efficiency and product quality.
The project will apply DTE’s patented liquid phase laser-induced breakdown spectroscopy (known as LP-LIBS) for furnace applications to gather real-time chemical composition analysis of molten aluminum—to make process control more precise, increase throughput, and raise product quality. And of course, to raise profitability too, it is hoped.
This pilot stage follows a memo of understanding signed by DTE and Arconic in October 2024. Their collaboration is being coordinated by the Arconic Technology Center in Pittsburgh, which will evaluate the potential for broader deployment of DTE technology across Arconic’s global manufacturing network.
So there you have three quick examples of significant metallurgical developments that are on the cusp of commercial impact—demonstrating that the progress we seek very often happens at a subatomic level, and yet may have outsized influence on your work or results.
About the Podcast
Great Question: A Manufacturing Podcast offers news and information for the people who make, store and move things and those who manage and maintain the facilities where that work gets done. Manufacturers from chemical producers to automakers to machine shops can listen for critical insights into the technologies, economic conditions and best practices that can influence how to best run facilities to reach operational excellence.
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About the Author
Robert Brooks
Robert Brooks has been a business-to-business reporter, writer, editor, and columnist for more than 20 years, specializing in the primary metal and basic manufacturing industries. His work has covered a wide range of topics, including process technology, resource development, material selection, product design, workforce development, and industrial market strategies, among others. Currently, he specializes in subjects related to metal component and product design, development, and manufacturing — including castings, forgings, machined parts, and fabrications.
Brooks is a graduate of Kenyon College (B.A. English, Political Science) and Emory University (M.A. English.)