RECENT ADVANCES IN BERYLLIUM METALLURGY

Journal Article · Sat Oct 01 04:00:00 EDT 1960 · J. Metals

OSTI ID:4129697

Gelles, S H; Pickett, J J; Wolff, A

Research on beryllium at Nuclear Metals, Inc., is described with particular reference to the problem of producing a more ductile crystal structure than the hexagonal close-packed structure normally found at room temperature and to the problem of discovering the cause of brittleness. Attempts were made to stabilize the bcc phase, which is inherently more ductile than the hexagonal close-packed phase, to temperatures lower than 1250 deg C by alloying. Partial success was attained in that the Ni-Be system was found to contain a bcc phase (beta) with an eutectic of approximately 1070 deg C at approximately 8 at.% nickel, but attempts to stabilize this phase by quenching beryllium-8 at.% nickel from approximately 1200 deg C were unsuccessful. The question of the effects of impurities on mechanical properties is next considered, and affirmative evidence for such effects is found in aging processes followed by electric resistivity measurements. Extruded beryllium rods were quenched and aged at temperatures between 200 and 1000 deg C, and resistivity vs. time data were collected. Large changes in resistivity were observed, especially at 600 deg C, indicating that precinitation processes are taking place; such processes are slow at 200 to 400 deg C, fast at 600 and 800 deg C, and do not appear at l000 deg C. Similar experiments were made and followed by mechanical strength tests, and the results again indicate impurity effects. The precipitation processes may explain the ductility decrease in the range 400 to 6O0 deg C. (D.L.C.)

• Research Organization: Nuclear Metals, Inc., Concord, Mass.
• NSA Number: NSA-15-000673
• OSTI ID: 4129697
• Journal Information: J. Metals, Journal Name: J. Metals Vol. Vol: 12
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BERYLLIUM
BERYLLIUM ALLOYS
BRITTLENESS
CRYSTALS
DUCTILITY
ELECTRIC CONDUCTIVITY
EUTECTICS
EXTRUSION
HEAT TREATMENTS
HIGH TEMPERATURE
IMPURITIES
MATERIALS TESTING
MEASURED VALUES
MECHANICAL PROPERTIES
METALLURGY
METALS, CERAMICS, AND OTHER MATERIALS
NICKEL ALLOYS
PHASE DIAGRAMS
PRECIPITATION
QUENCHING
RODS
TEMPERATURE
VARIATIONS