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Accession Number DE13-1098285
Title Ta-10W LEVBW Development.
Publication Date Oct 2011
Media Count 39p
Personal Author S. W. Pierce
Abstract Low voltage electron beam welding (LVEBW) is being developed as the joining process for a Ta-IOW strength member encapsulation layer in a heat source assembly. This presentation provides brief background of the strength member design considerations, covers parameter development through bead-on-tube, plate, and mockup welding, and provides results in the form of metallography, SEM, and tensile testing. Based on exploration of a range of settings extending from sharp focus at 80 ipm to +30 defocus at 30 ipm, a nominal parameter set consisting of 60kV, 100ma, sharp focus, and 60 ipm was found suitable for the 0.100 thick strength member joint. Tensile testing and subsequent SEM of the fracture surfaces revealed undesirable low ductility and brittle transgranular cleavage fracture of the weld metal. The low ductility of the weld was attributed to contamination of the base metal during vacuum furnace recrystallization and further contamination of the weld in the EB chamber. As a result of this work, efforts will made to secure the highest quality, recrystallized Ta-1 OW, implement cleaning and handling procedures, and investigate the EBW system for contamination sources.
Keywords Contamination
Electron beam welding
Heat sources
Low voltage electron beam welding(LVEBW)
Tensile testing

Source Agency Technical Information Center Oak Ridge Tennessee
NTIS Subject Category 41F - Joining
94G - Manufacturing Processes & Materials Handling
71 - Materials Sciences
Corporate Author Los Alamos National Lab., NM.
Document Type Technical report
Title Note N/A
NTIS Issue Number 1411
Contract Number DE-AC52-06NA25396

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