FUSION WELDING OF BERYLLIUM
Joining of beryllium (Be) plates by gas tungsten-arc braze welding and fusion welding with a-c current was investigated with the objectives of: evaluating the techniques for applications at temperatures up to 1300 deg F; and elucidating some of the factors affecting weld quality. Oxidation during welding was effectively controlled by means of an argon atmosphere inside a vacuum-tight dry box. Braze welds were made using filler strips of an aluminum-12 silicon (Al- - 12Si) alloy and of unalloyed silver (Ag), arc melted in place. Using either filler metal, room temperature tensile strengihs in the direction transverse to the weld were found to be in the range 20 000 to 25 000 psi under optimum conditions. Although Al-- 12Si braze welds do not appear to be useful for elevated temperature applications, transverse tensile strengths of Ag braze welds amounting to about 11 000 psi at 1300 deg F, which is more than 80% of the base metal strength at this temperature, indicate a potential usefulness for such applications. The tendency toward tearing and cracking during fusion welding was found to be reduced by increasing preheat temperature and by decreasing speed and current, as long as comparisons are made between fusion zones of similar size and geometry. The tendency toward tearing and cracking a1so decreased with decreasing fusion zone size, as measured by penetration. However, with current maintained constant at 150 amp, the effect of increasing speed counteracted the associated decreasing penetration, so that no change in tearing occurred. Additions of aluminum (Al) to the fusion zones in amounts of about 1% or less were found to promote tearing. Variations in the susceptibility to tearing encountered in the various lots of Be tested were attributed to variations in the Al content. (auth)
- Research Organization:
- Avco Corp., Wilmington, Mass.
- NSA Number:
- NSA-18-014449
- OSTI ID:
- 4084064
- Journal Information:
- Welding J. (N.Y.), Journal Name: Welding J. (N.Y.) Vol. Vol: 43
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
Similar Records
INVESTIGATION TOWARD OBTAINING SIGNIFICANTLY HIGHER MECHANICAL PROPERTIES OF AS-WELDED JOINTS IN HIGH-STRENGTH, HEAT TREATABLE ALUMINUM ALLOYS
WELDING OF BERYLLIUM. METHODS STUDIED AND THE RESULTS OBTAINED DURING THE INITIAL INVESTIGATION OF BERYLLIUM JOINING BY VARIOUS METHODS ARE PRESENTED
Related Subjects
ALUMINUM
ALUMINUM COMPOUNDS
ARGON
BERYLLIUM
BRAZING
CEMENTS
CONFIGURATION
CONTROL
CRACKS
CURRENTS
DIFFUSION
ELECTRIC ARCS
FLUIDIZATION
FREQUENCY
GASES
HIGH TEMPERATURE
INERT GASES
JOINTS
MATERIALS TESTING
METALS, CERAMICS, AND OTHER MATERIALS
OXIDATION
PLATES
PRESSURE
SILICIDES
SILVER
TENSILE PROPERTIES
TUNGSTEN
USES
VACUUM
VARIATIONS
VELOCITY
WELDING