Scientists at the U.S. Department of Energy's (DOE) Oak Ridge National Laboratory (ORNL) have developed a method that uses additive manufacturing (AM), or 3D printing, to fabricate custom canisters for powder metallurgical hot isostatic pressing (PM-HIP), streamlining production of large-scale metal components used in aerospace, energy and medical applications.
PM-HIP is a process that consolidates metal powder into fully dense parts such as turbine components, pressure vessels and other large structural parts using high temperature and pressure inside a sealed container, or canister. Traditionally, producing these canisters requires multiple steps - including metal forming, machining and welding - which can introduce defects, increase costs and limit design flexibility.
The ORNL team used AM to fabricate these canisters instead. This approach enables precise, complex geometries tailored to the final component while eliminating multiple manufacturing steps. As a result, parts can be produced closer to their final shape, minimizing material waste and shortening production time.
After printing, the canister is filled with metal powder, vacuum-sealed and processed in a hot isostatic press. Heat and pressure compress the powder into a solid metal component with minimal internal defects, producing large, structurally robust parts. Until now, the application of AM in fabricating HIP canisters has not been explored.
"This work lays the foundation for a transformative shift in the PM-HIP landscape for large-scale components," said ORNL researcher Pavan Ajjarapu. "By harnessing the strengths of both additive manufacturing and hot isostatic pressing, we are paving the way for greater design freedom and expanded applications in hydropower and next-generation nuclear reactors."
The team successfully used AM to fabricate canisters using several types of 3D printing, including laser- and wire-based methods. The canister then undergoes the standard PM-HIP process to produce a fully dense metal component. These components are designed for demanding applications in energy and aerospace systems, where strength, reliability and performance under extreme conditions are critical.
PM-HIP also enables the use of advanced alloys that can be engineered for enhanced resistance to corrosion. Researchers can control the material's internal structure, tailoring properties such as radiation resistance and stability at high temperatures that are essential for nuclear applications.
Innovation strengthens U.S. manufacturing, supports national security
"This approach offers an alternative to casting and forging," said ORNL's Soumya Nag. "It could also help strengthen U.S. manufacturing and national security by easing supply chain shortages."
Another key advantage of PM-HIP technology is its ability to predict shrinkage and distortion when producing large, nearly finished parts.
"A deeper understanding of how the PM-HIP process works can help eliminate uncertainties related to these predictions," said Subrato Sarkar, an ORNL researcher who is developing custom models to predict how parts may distort or change shape using simulations of heat and pressure during processing.
ORNL's Jason Mayeur added: "We further enhanced the effectiveness of PM-HIP technology by using a mechanics-based computational model to reduce developmental costs and lead times by eliminating trial-and-error approaches." This model enables more precise predictions, allowing for optimized processing and improved outcomes in manufacturing large-scale parts. For more information on the computational modeling aspects of this research, see the team's article in Powder Technology .
In addition to Ajjarapu, Sarkar, Mayeur and Nag, the research team includes Fred List III, Sam Bell, Peeyush Nandwana, Sebastien Dryepondt, Andrzej Nycz, Chris Masuo, Thomas Feldhausen, Mithulan Paramanathan, Kevin Hanson, Chase Joslin, Brian Jordan and Ryan Dehoff. Additional ORNL contributors include Chelo Chavez, Amir Ziabari, Pradeep Ramuhalli, Hongbin Sun and Chris Tyler.
Building on a legacy of PM-HIP innovation
This study builds on years of previous PM-HIP research at ORNL, highlighted by the 2024 moonshot project . In that project, researchers successfully printed a 2,000-pound hydropower impeller canister prototype from initial design to finished part in just two days, showcasing the potential of these innovative technologies.
To advance this promising field, ORNL convened 200 stakeholders last year at DOE's Manufacturing Demonstration Facility (MDF) at ORNL to discuss the future of PM-HIP. The workshop focused on identifying gaps, challenges and opportunities to advance the technology for large-scale, complex metal components.
This project is supported by DOE's Office of Nuclear Energy, Advanced Materials and Manufacturing Technologies program. MDF, where this work was conducted, is supported by DOE's Advanced Materials and Manufacturing Technologies Office and acts as a nationwide consortium of collaborators focused on innovating, inspiring and catalyzing the transformation of U.S. manufacturing.
UT-Battelle manages ORNL for DOE's Office of Science, the single largest supporter of basic research in the physical sciences in the United States. The Office of Science is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science . - Tina M. Johnson
