SOLID STATE WELDING OF BERYLLIUM

Journal Article · Mon Apr 01 04:00:00 EST 1963 · Welding J. (N.Y.)

OSTI ID:4740195

Passmore, E M

The welding of both hot-pressed and hot-pressed and extruded beryllium powder was investigated, using the differential thermal expansion between the beryllium specimens and a molybdenum clamp to hold the adjoining surfaces in contact while induction heating in vacuum. The most complete bonding was observed to result when intimate contact across the weld interface was achieved using metallographically polished adjoining surfaces. Weld tensile strength was found to be closely dependent on prior roughness of the adjoining surfaces, welding temperature, and base metal strength. When the adjoining surfaces were prepared by mechanical polishing, weld strength was found to increase with increasing welding temperatures up to the range 900 to 975 nif- C. Above 975 nif- C strength decreased because of grain growth in the base metals. The maximum strengths were equal to those of the base metals--- about 40,000 psi for hot pressed and about 60.000 psi for extruded beryllium, respectively. The attainment of weld strengths equal to those of the base metals with little plastic deformation and no observable grain growth across the interface during welding indicates that the bonding mechanism involves the attainment of atomic contact across the interface. This contact is probably facilitated by the occurrence of some localized plastic deformation and surface diffusion. However, no direct evidence of these processes was observed. The rapid initial increases in weld strength with increasing welding temperature are attributed largely to the decreasing yield strength and increasing atomic mobility of the beryllium; this results in increasing contact area at the interface during welding. (auth)

• Research Organization: Manlabs, Inc., Cambridge, Mass.
• NSA Number: NSA-17-018727
• OSTI ID: 4740195
• Journal Information: Welding J. (N.Y.), Journal Name: Welding J. (N.Y.) Vol. Vol: 42
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ATOMIC MODELS
BERYLLIUM
BONDING
CLEANING
CONFIGURATION
DEFORMATION
DIFFUSION
EXPANSION
EXTRUSION
GRAIN SIZE
HEATING
HIGH TEMPERATURE
HOT WORKING
INDUCTION
METALLOGRAPHY
METALS, CERAMICS, AND OTHER MATERIALS
MOLYBDENUM
POWDERS
PREPARATION
SURFACES
TEMPERATURE
TENSILE PROPERTIES
VACUUM
WELDING
WELDS