Additively Manufactured, Net Shape Powder Metallurgy Cans for Valves Used in Energy Production

Additive manufacturing (AM) has the potential to enable a paradigm shift in fabricating complex net shape components with yields over 90%, significantly increasing productivity, decreasing energy consumption during manufacturing and improving downstream energy efficiency. ORNL has developed a technology for producing large-scale additively manufactured polymer matrix composite components at deposition rates on the order of 100 lbs. per hour. This project utilized tools, dies and molds made from this technology to enable the net shape forming of cans for the powder metallurgy (PM) manufacturing of valves used in energy production plants. This approach has the potential to develop affordable valves with superior performance to castings. It will also lead to increased strength values, decreased wall thickness size, and the potential for higher yields (less machining). This project is critical for evaluating new methodologies for the fabrication of additively manufactured tooling, molds and dies that could be used across multiple industries. In the first phase of this project, a new methodology of creating a Powder Metallurgy and Hot Isostatic Pressing (PM-HIP) container by hydroforming sheet metal over additively manufactured (AM) dies was evaluated. The goal in this stage of development was to evaluate some of the new polymer matrix composite materials designed for deposition on large scale additive manufacturing systems as candidates for hydroforming steel and aluminum sheet to make thin gauge net shape components. In order to meet this objective, most research was performed on subscale tools in order to evaluate the processing pressures, material options, and gauge thicknesses most relevant to this approach. In addition, full scale AM tools (30% over final component geometry) were produced to demonstrate scalability, but were not used in testing. The first phase of this project has proven this concept has merit, but future studies are required to address minor tool failures that occurred in phase one due to geometry, cost of the process over other techniques, and demonstration of a full-scale tool that could then be used in (HIP). Lastly, this project provides the PM community a new approach in using hydroforming for the manufacturing of cans, a process that was not highly utilized for this purpose previously.