SBIR-STTR Award

Advanced manufacturing is essential for the Department of Energy’s initiatives to improve nuclear energy's cost, safety, and efficiency. Research and eventual deployment of small modular reactors, sodium cooled reactors, and molten salt integral safe reactors requires high quality welding of high temperature metal alloys, such as Inconel 718, and new methods for metal additive manufacturing of high temperature metals and metal alloys. Such technologies already exist: electron beam welding and electron beam metal additive manufacturing. The electron beam melting process enables the fabrication of high temperature, high strength metals, such as nickel based alloys and niobium. However, such e-beam processing is expensive and of limited accessibility. U.S. Electron is developing an electron beam system that mitigates the current limitations of electron beam welding and additive metal manufacturing. U.S. Electron is commercializing a novel electron beam gun (?e-gun?) for electron beam processing, including welding and additive manufacturing. The distinguishing feature of the U.S. Electron's e-gun is that it operates in a soft vacuum of ~1 to 2 torr, many times higher pressure than conventional e-beam systems. This allows the electron beam to operate inside of a simple snorkel that moves over a weld or assembly area, and eliminates the need to enclose the entire part inside of an expensive vacuum housing. The Company's e-gun and snorkel also provide a solution for precise, large area metal additive manufacturing. In Phase I, U.S. Electron will retrofit a novel component, a DBD cathode, into a standard electron gun typically used for e-beam welding and 3D metal printing. This effort requires specialized mechanical designs and custom high voltage power systems engineering. The Company will demonstrate that its new DBD e-gun can operate in soft vacuum (~1 to 2 torr) and weld metal samples. During Phase I, U.S. Electron will also design the snorkel housing for use in Phase II. Use of U.S. Electron’s e-gun will lower the capital and operating costs of e-beam systems by eliminating the need for large vacuum housings. DBD e-gun systems will be field-deployable; able to be moved amongst multiple manufacturing facilities or installed at construction sites. This will allow manufacturers to build large systems in place using high quality electron beam joining or additive metal manufacturing while simplifying their shipping logistics. The DBD e-gun can be retrofit into existing e-beam systems for welding or 3D printing. U.S. Electron's system is field deployable, cost reducing, and drastically improves e-beam productivity, especially when joining special alloys such as high temperature nickel alloys used in nuclear reactors.

Electron beam (“ebeam”) welding and 3-D metal printing are advanced manufacturing processes critical to the aerospace, energy, and security industries because of their ability to process advanced metals with high precision. They are also important for the Department of Energy’s initiatives to develop small modular and integrally safe reactors. However traditional ebeam systems are large, slow, and expensive. These limitations arise from the need for conventional electron sources and target parts to operate inside high vacuum chambers; the larger the part, the larger the chamber. An electron source not requiring a high vacuum would enable smaller, faster, and more affordable electron beam systems. The purpose of this Project is threefold: 1) Design, build, and test a novel electron source to operate under vacuum requirements much less stringent (a “soft vacuum”) than those of traditional ebeam systems; 2) Design, build, and test a snorkel-like, soft vacuum chamber to transport electrons emitted by the novel source and which is attached to the target with a soft, moveable vacuum seal; 3) Combine the novel electron source and snorkel into an prototype integrated ebeam welding system and demonstrate welding. In Phase I, the novel electron source was designed, fabricated, and successfully operated at full power, including extraction of electrons. The snorkel was also designed. However government-mandated “shelter in place” orders delayed the final tests of the ebeam’s interaction with a metal target. These tests will be completed when the government orders are lifted. In Phase II, a next generation of the electron beam source will be designed and fabricated, using lessons learned from Phase I. This new electron source will be installed in the snorkel, which will be fabricated in Phase II. The combined system will then weld a model high- temperature alloy, with the resulting weld evaluated and certified using international welding standards. U.S. Electron is developing an electron beam system that mitigates the limitations of current electron beam processing by eliminating the requirement for high vacuum conditions and large enclosures. This will lead to a reduction in cost and complexity for ebeam processing. Simpler, easier to maintain, lower cost vacuum “roughing” pumps will replace high cost, complex, high-vacuum pumps. Drastically reducing pump- down times will increase the throughput of these systems, enabling lower cost, higher volume applications. Finally, reducing the high vacuum requirement reduces the size of ebeam systems, enabling flexible, field deployable ebeam welding applications, such as the performing long and/or deep welds on rockets and naval vessels, the on-site welding of large nuclear reactor vessels, and in-the-field repair of crucial aerospace components.