Electron Beam Delivery System with In-Situ Metrology and Real Time Closed Loop Process Control for Metal 3D printing and welding of large components to high accuracy and verifiable quality

A methodology based on dynamic electron beam imaging of beam-component interactions for in-situ metrology and closed loop real time process control of electron beam wire printing and welding applications in space has been demonstrated at the proof of concept level with hardware, controls and software developed by COSM in Phase I and II programs.A new Electron Beam Delivery Unit (EDU) that has both the beam current, spot size and multiplexed scan capability for high resolution imaging and the power required for wire based 3D printing and welding. The EDU will be designed from Phase IIX/III modelling and in collaboration with end user and program insertion requirements including mechanical design for launch load and thermal excursions and compatibility with input power available from various platforms envisioned for future NASA missions in the Moon to Mars programElectron beam scan control and image acquisition hardware that will enable simultaneous wire melt or weld and image data capture. Integration of beam control and real time inspection/flaw detection data capability by means of detecting secondary and backscattered electrons which can be continuously fed in real time into the process.nbsp;This results in the capability for real-time process monitoring and identification of external and internal flaws, dimensional measurement data and other material attributes which will be critical for obtaining acceptance and certification concurrent with part fabrication.nbsp;These signals have the potential to be used for many forms of both metrology and process control on all aspects of system operating parameters and component quality measurement with data available to be sent to earth for analysis and reference of long-term reliability. The combination of these innovations will provide the capability to produce known good large parts, modify or repair broken components, and assemble large structures by welding in space, on an orbiting platform, and on the Moon and Mars.