A Coaxial Wire-Feed Additive Manufacturing of Metal Components Using a Profile Electron Beam in Space Application

Despite the variety of different methods of metal 3D printing on Earth, only a few of them can be realized in space. Processes that employ electron beam as a heat source and wire as a consumable material is among the most promising methods for these applications. But to date, such processes still have not been implemented in actual space operation, mainly due to the low accuracy and resolution of these 3D printed products that require significant post-processing for their intended use. Large and heavy hardware employed in these processes is another significant problem. xBeam 3D Metal Printing is the electron beam DED-wire additive manufacturing technology that has already demonstrated the capability to produce high-quality parts with high productivity on terrestrial relatively lightweight and compact hardware. xBeam process employs a profile electron beam generated by low-voltage gas-discharge electron beam guns combined with the coaxial wire feed to provide excellent control of metallurgy processes in the melt pool and around it during deposition. Realized metallurgy conditions are the crucial factor in providing the combination of high accuracy and resolution with good metal structure and properties. Moreover, maintaining such metallurgy conditions does not require gravity—only cohesion/adhesion forces and surface tension forces are involved. This fact suggests good prospects for using the xBeam 3D Metal Printing in space applications. In addition, the method opens several unique technological opportunities that are important in space exploration, including the nonstick deposition technique allowing the production of "ready-to-use" parts, surface glazing able to substitute machining, recycling of the metal waste directly into wire for 3D printing, and others. The article presents technical solutions for implementing 3D printing and related processes in space conditions and analyzes the metallurgical aspects of the technology using titanium alloy Ti-6Al-4V as an example.