Why start with a plastic shape when the goal is a metal component? In a process developed by Oak Ridge National Laboratory and A.J. Tuck Company, a 3D-printed polymer form supplies the geometry. Electroforming copies that geometry into a nickel shell, and the shell becomes a container for processing metal powder.
Three objects do different jobs: the printed form defines the shape, the hollow nickel HIP can contains the powder, and the final metal component forms when that powder consolidates under heat and pressure. Following these roles explains where 3D printing contributes.
Print the geometry, then build the shell
The team first 3D-prints a polymer mandrel, or form. Polymer additive manufacturing can create complex geometries that would be difficult to produce conventionally. The printed form goes into an electrolyte bath, where electroforming uses electricity to build a dense nickel shell that replicates its surface.
The nickel layer is approximately 2–3 millimeters thick. A.J. Tuck Company provided electroforming and metal-processing expertise and performed the project's electroforming activities.
Once the shell is formed, the polymer is removed. In this project, the team dissolved it with acid, leaving a hollow nickel structure. That empty structure is the HIP can, ready to receive metal powder.
The can enables the next transformation
HIP stands for hot isostatic pressing. In powder metallurgy HIP, metal powder is sealed inside a container and exposed to high heat and pressure. The particles fuse into a fully solid piece close to the desired final shape.
The sequence therefore passes geometry from a printed polymer form to an electroformed shell, then uses the shell to contain powder during consolidation. ORNL's account does not specify the post-HIP treatment of the can.
Why use polymer printing first?
ORNL reports that working with plastic for the initial form reduces material strain and distortion compared with directly printing metal at extremely high temperatures. It also describes lower material and equipment costs, faster design changes, and less post-processing than metal-based additive manufacturing systems. The article gives no numerical cost or time saving for an entire production line.
Conventional HIP-can production involves several fabrication and assembly steps. Here, polymer printing supplies the geometry and electroforming builds the metal container around it. The manufacturing advantage being explored is how these processes work together.
Five cylinders and an integrated port
In phase one, the team electroformed five leak-free cylindrical HIP cans, each 6 inches high and 4 inches in diameter. It also developed an integrated port design that eliminates separate welding of process tubes. The source identifies those separate tube welds as a common source of failure during HIP; the improvement concerns that specific joining step.
Phase two, now underway, will apply the process to a more complex geometry: either an impeller, a rotating component that moves fluid in equipment such as pumps and turbines, or a valve relevant to nuclear energy systems. The demonstrated result is five leak-free cylindrical cans. Extending the process to those complex shapes remains the next stage.
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