ORNL Continues Developing DuAlumin-3D

Oak Ridge National Laboratory (ORNL) has reported progress with DuAlumin-3D. The team has said that,

“DuAlumin-3D outperforms traditional alloys, which are prone to cracking during laser powder bed fusion processing, while maintaining comparable heat characteristics. This advancement offers lightweighting solutions and reduces fuel costs,” the company stated, adding that the alloy “exhibits superior strength and resistance to deformation at elevated temperatures, outperforming all known aluminum alloys.”

According to researcher Alex Plotkowski,

“DuAlumin-3D performed exceptionally well in our evaluations. While our research focused on its use in high-efficiency engines, it could also be used for lightweighting applications in aerospace and to optimize heat exchangers.”

DuAlumin-3D is an alloy that has been created to maintain properties at use temperatures above 300°C. The alloy is optimized by changing LPBF parameters and a quick (stated as eight hour) heat treatment, which improve the nanoscale microstructure and precipitates, respectively, to improve its properties. These types of alloys are also known as HiFi alloys because they have high fractions of intermetallics. The alloy has been tested on pistons and other engine components by General Motors and Honda Racing. Work was done at ORNL in collaboration with Beehive Industries and the University of Tennessee. With excellent corrosion, heat, tensile, creep, and fatigue properties, plus reduced cracking, it’s kind of a Cinderella material that could be extremely fast and therefore cheap to print, while producing superior properties in parts compared to other materials that are far more expensive per kilogram and much slower to print.

In pistons, it has been able to produce lighter pistons with 50% greater High Cycle Fatigue strength than cast parts. This is especially significant since we generally produce parts with poor fatigue strength with additive manufacturing. The work was made possible by the US Department of Energy‘s (DoE) Office of Energy Efficiency and Renewable Energy, through its Vehicle Technologies Office (VTO) and Advanced Manufacturing Office, as part of the VTO Powertrain Materials Core Program. The material was alloyed by Eck Industries and atomized by Connecticut Engineering Associates. Eck Industries is a casting and forging provider that does specialized Department of Defense (DoD) work and has received SBIR awards for MMC (Metal Matrix Composites) and other materials. The company got an SBIR Phase II award of $721,000 to produce Aluminum-Cerium (Al-Ce) alloys and another $100,000 award to use that material for military castings.

DuAlumin-3D is an Al-Ce alloy, using the rare earth element Cerium. Al-Ce alloys are a real focus area for the DOE, and the agency has been working with ORNL, Lawrence Livermore National Laboratory (LLNL), Ames, and others on this research since at least 2020. It is also generally very interested in what it types as Al REE, aluminum rare-earth elements more generally. Cerium is mined in the US and is available there on a large scale; utilizing it for car parts greatly brings down the costs of US ships, missiles, and planes that may need high-performance aluminum.

If the US can industrialize comparatively low-cost, rare-earth-enhanced alloys, it would be very beneficial for the government. Better American products, with less dependence on Chinese Rare Earths, would be very beneficial. At the same time, maybe the US could take the lead in making this material super low-cost to produce. Then, the amount and type of parts would expand significantly, allowing the US to move ahead with additive manufacturing generally. It’s a good, big-picture play that could pan out well for the US. With more attention being directed at friend and nearshoring, as well as reshoring materials like this, it could be very advantageous.

DuAlumin-3D is not Cerium alone, but Al-9Ce-4Ni-0.5Mn-1Zr. With manganese, zirconium, and Niobium in the mix, it could be more complex to source generally. Zirconium and manganese are easy to source, while Niobium is a bit harder, but all three are quite abundant and easy to access. Titanium, by comparison, is much more difficult (while Russia is a key supplier). There is another advantage in using something new and exotic as well. If the Chinese were to steal an STL for an additive component in titanium, it would be easy for them to print and source. They will probably have already built up a lot of expertise with that material, especially since it has been used extensively in aircraft and is readily supplied by Russia. But, DuAlumin-3D would require new work in creating the alloy, designing for it, and printing it, which could retard adoption. It would also be pretty easy to spot their activity.

Aluminum has been gaining in importance as a 3D printing material due to its low cost (of the material itself), its prevalence, its desired properties, and the high speeds at which it prints. The adoption of designer aluminum has been slowed somewhat due to its not quite matching other materials in certain performance criteria. With DuAlumin-3D, ORNL could move aluminum alloys into the driving seat in the high-performance world as well.