FUNDAMENTAL STUDIES IN HIGH-ENERGY ELECTRON-BEAM WELDING

WELDING USING HIGH-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 ACCOMODATED BECAUSE OF THE DEEPER PENETRATION INTO THE WORKPIECE OF HIGHER-ENERGY BEAMS. THE OBJECTIVE OF THIS PROPOSED EFFORT IS TO FURTHER EXPLORE THE POTENTIAL OF HIGH-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 "ILLUMINATE" THE WELD PROGRESS. THE END PRODUCTS OF THIS EFFORT 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 CONTITUTE 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.