Additive Manufacturing of Functionally Graded Parts for High Performance Applications

In recent years, the nuclear power industry has been exploring the use of conventional powder metallurgy and hot-isostatic press technologies to fabricate large, near net shape components for high pressure components and other applications pertaining to the generation of electric power. Powder metallurgy has many manufacturing consistency and reliability advantages over other large-scale manufacturing methods (e.g. casting, welding, forging etc.), which include the fabrication of near-net shape parts with controlled chemistry and improved microstructure in the part. Despite the advantages, there are drawbacks to todayÆs powder metallurgy/hot isostatic press processes. Large-scale parts are manufactured using these technologies by first fabricating a conformal can, or mold, in a size slightly larger than shape of the part. The can is then uniformly filled with metal powder and evacuated, sealed, and placed in the hot isostatic press for processing.ĀIn general, the geometry of the parts fabricated in this process is limited by the mold geometry and the ability to uniformly fill the mold with metal powder, which is critical to the quality of the part. In the Phase I project, a novel multi-material 3-dimensional (3D) additive manufacturing (AM) process was combined with powder metallurgy/hot isostatic press (HIP) technology; enabling the fabrication of parts not possible with conventional techniques. Geometrically complex metal parts were fabricated by multi-material printing metal and supporting powders in inexpensive steel and 3D printed molds and processing the molds using a HIP.Ā In the Phase II project, Grid Logic will build upon the multi-material AM-HIP technology foundation established in the Phase I effort to develop a state-of-the-art multi-material powder printhead capable of printing a variable mixture of two metal powders during the 3D printing process. This technology will enable the fabrication of next-generation, high-performance parts with functional gradients of metal alloys in the body of the part. Further, this new additive manufacturing technology will allow for parts to be designed such that the required high-performance materials properties are located only where it is necessary in the part, which has the potential to both reduce cost and improve operating performance. Commercial applications of this new additive manufacturing process include the fabrication of high-performance, functionally-graded parts for commercial and federal customers, and the development of a new additive manufacturing process that will allow for the low-volume manufacturing of reproducible, high quality, geometrically complex near-net shaped parts at a reduced cost as compared to conventional manufacturing methods.