SBIR-STTR Award

Welding using hlgh-energy (10-20mev) electron beams offers potential advantages over conventional electron-beam welding technologies. Potential advantages of high-energy electron beam welding include the capability of making very high quality welds in very thick and/or large workpieces at or above atmospheric pressures. The use of a high-energy electron beam obviates the need for the near-vacuum environment required by conventional electron-beam welding. Thicker workpieces can be accommodated because of the deeper penetration into the workpiece of higher-energy beams. The oblective of this proposed effort is to further explore the potential ofhigh-energy electron beam welding by (1) analyzing the interaction between the high-energy electron beam and metals and (2) developing a preliminary design for a real-time process monitor based on the use of the x-rays emitted by the beam to illuminates the weld progress. The end products of this export will be (1) an improved understanding of the relevant interaction physics; and (2) the basis for the engineering design and construction of prototype monitor hardware. These end products will constitute the foundations both for a Phase II SBIR effort and for exploratory development of a prototypical heebw system. High energy electron beam welding has the potential to facilitate making welds of very high quality in very large and/or thick workpieces. The x-rays emitted by the beam in interacting with the workpiece can be used to monitor the progress of the weld in real time. These features will provide enhanced welding capabilities in many government and commercial applications; shipbuilding is an excellent example.

Welding using high-energy electron beams (HEEBs) offers potential advantages over conventional electron-beam welding (EBW) technologies, including making very high quality welds in very thick and/or large workpieces at or above atmospheric pressures (i.e., no vacuum vessel required) within a variety of controlled working gas environments. Thicker workpieces can be accommodated more easily than with conventional EBW technologies because HEEBs offer more robust and deeper propagation into the workpiece. The objective of this effort is to (1) fabricate and demonstrate a real-time process monitor that uses the x-rays emitted by the beam to "illuminate' the weld in progress and (2) analyze further the interaction between the high-energy electron beam and the workpiece. A preliminary monitor design developed in Phase I is discussed in this report. The results of this effort will be (1) a firm basis for the engineering design and construction of prototype HEEB welding x-ray monitor hardware, and (2) a improved understanding of the HEEB/workpiece interaction physics that provides the basis for a judgement concerning the fundamental utility of high-energy beam welding processes. These end products are basic constituents of a prototypical HEEB demonstration facility. Anticipated

Benefits:
Industries that would benefit directly from HEEB welding and materials processing include auto makers, airplane manufacturers, composite manufacturers, the nuclear industry, the railroad industry, ceramics manufacturers, shipbuilders, and the electric transformer industry, to name a few. The x-ray imaging monitor is a critical element of a feasible HEEB system in that it provides a real-time, remote means of assessing welding or materials processing operations.