Development of Welding and WA-DED process for fabricating compositionally graded structure for nuclear application.

In this Phase I STTR, Solvus Global will partner with Pacific Northwest National Laboratory (STTR Research Institution) and Idaho National Laboratory to develop wire-arc direct energy deposition technology to fabricate bimetallic structural materials (e.g., Haynes 244 and Alloy 709) for advanced nuclear reactor applications. The Solvus-PNNL-INL team has the combined expertise, capability, and experience in advanced nuclear materials and manufacturing needed for a successful program. The adoption of new structural materials with superior performance is vital for building next-generation nuclear reactors, as these materials offer improved mechanical, thermal, and radiation-resistant properties needed to endure extreme operational environments. However, fabricating complex components, such as bimetallic or functionally graded structures, from these materials poses challenges with conventional manufacturing methods. The graded structures, which feature spatially varying compositions or microstructures, offer several advantages in nuclear applications, including improved thermal stress management and enhanced overall material performance. Traditional manufacturing techniques lack the precision and flexibility required to achieve the gradual transitions needed for making these structures. Additive Manufacturing (AM) offers a potential solution to address these limitations and accelerate the adoption of advanced materials in nuclear applications. When applying AM to nuclear components, part size and process limitations need to be considered. For applications requiring large-sized parts, powder-based AM techniques such as Laser Powder Directed Energy Deposition (LP-DED) and Laser Powder Bed Fusion (LPBF) face limitations in terms of build scale and speed, and methods capable of producing larger build volumes and higher deposition rates are needed to meet the manufacturing needs. Solvus Global aims to solve these problems through manufacturing a gradient structure using Wire Arc-Directed Energy Deposition (WA-DED) and welding to achieve desired combination of properties that otherwise cannot be attained by a single material alone. WA-DED stands out with its ability to produce the large build volumes among AM processes. WA-DED process has several advantages over conventional manufacturing in adapting new materials and fabricating functionally graded structures due to the use of conventional welding equipment and feedstock coupled with the ability to switch to different material by simply changing the feedstock. Thus WA-DED can be a promising alternative to conventional methods for fabricating functionally graded structures of next generation of materials such as Ni 244 and A709 for nuclear power generation.