With industries like clean energy, aerospace, and defense needing larger and more advanced metal components, the Oak Ridge National Laboratory (ORNL) is leading the way in bringing some serious innovation back to U.S. manufacturing. Using a combination of powder metallurgy-hot isostatic pressing (PM-HIP) and cutting-edge 3D printing techniques, ORNL is offering a high-precision alternative to old-school casting and forging methods.

Since much of the casting and forging work has moved overseas, the U.S. now faces supply chain hiccups when trying to source massive parts—especially those weighing over 10,000 pounds. ORNL’s approach is all about solving that problem, with PM-HIP giving manufacturers more control over designs and letting them build more complex shapes. The process starts by creating molds—called “cans”—using wire arc additive manufacturing (WAAM) or hybrid additive-subtractive methods. These molds are filled with metal powders, sealed up, and then sent through a hot isostatic press (HIP) for high heat and pressure treatment.

This HIP method is different from traditional forging because it bonds the powders into solid parts without needing to melt them, meaning it can create more precise shapes with less chance of defects. On top of that, the flexibility to combine multiple materials in a single part makes it perfect for demanding applications, like those in aerospace or energy, where high performance is non-negotiable.

Tackling Shrinkage with Smart Simulations

One of the biggest challenges in PM-HIP is dealing with how much the metal powders shrink during the process—sometimes by as much as 30%. This shrinkage isn’t always consistent, especially with complex designs, making it tricky to get the dimensions just right. Jason Mayeur, a senior researcher who specializes in computational solid mechanics, has developed simulations to predict how parts will shrink based on their shape. His work helps adjust the mold designs upfront to make sure the final product turns out exactly as intended.

“PM-HIP offers a controlled pathway for producing large-scale metal parts that have become increasingly difficult to source through conventional methods,” says Mayeur. His modeling helps fine-tune things like heat and pressure settings, ensuring the process works smoothly across different metal alloys.

Meanwhile, metallurgist Soumya Nag handles the hands-on side of things, focusing on how the PM-HIP method performs in real-world tests. His job involves making sure the metal powders used can stand up to the high heat and pressure they experience in the HIP process. By studying the microstructures and mechanical properties of the finished parts, Nag helps make sure they meet the strict requirements of industries like energy and defense.

“By combining the design flexibility of additive manufacturing with the reliability of PM-HIP, we can produce large-scale, custom parts tailored for energy and defense applications,” Nag explains. The teamwork between Mayeur’s computer models and Nag’s experimental research ensures ORNL stays on the cutting edge of this technology.

Boosting U.S. Manufacturing and Decarbonization Goals

Being able to make high-quality metal parts domestically not only strengthens the U.S. supply chain but also reduces dependence on overseas suppliers. Industries like nuclear power, aerospace, and hydropower will benefit from PM-HIP’s ability to build tough components—like pressure vessels and impellers—that can handle extreme conditions. With these better-performing parts, companies can boost durability and cut down on issues like thermal fatigue.

ORNL’s work also supports the Department of Energy’s mission to cut carbon emissions. By using high-performance materials in the energy sector, PM-HIP helps build more efficient, lower-emission systems. Plus, producing these parts locally shrinks the carbon footprint tied to international shipping and long supply chains.

To speed up adoption and tackle any remaining challenges, ORNL is hosting a workshop on October 9-10, 2024, at its Manufacturing Demonstration Facility (MDF). The event, supported by the Metal Powder Industries Federation and the Electric Power Research Institute, will bring together researchers, manufacturers, and policymakers to explore how PM-HIP can be expanded across different industries.

This workshop is part of a broader push by ORNL, backed by the Department of Energy’s Advanced Materials and Manufacturing Technologies Office (AMMTO), to promote next-generation manufacturing. By fostering collaboration between industry and academia, the event aims to identify research priorities and move the technology closer to real-world use.

With ORNL at the forefront, the future of large-scale metal manufacturing looks promising—and it’s happening right here in the U.S.