ANNEALING OF VACANCIES IN QUENCHED ALUMINUM-MAGNESIUM ALLOY

Technical Report · Sun Sep 01 04:00:00 EDT 1963

OSTI ID:4149921

Eikum, A K

Vacancy climb of prismatic helicoidal dislocations and prismatic dislocation loops in aluminum-5 wt.% magnesium was studied using transmission electron microscopy. From both bulk annealing and thin foil heating stage experiments, the magnesium-vacancy binding energy E/sub b/ was estimated to be 0.10--0.20 ev. Helices and loops appear to grow in thin foils just as they do in bulk specimens, which is possible if local vacancy supersaturation can be maintained around the climbing dislocations. Above 250 deg C, loop growth can be described by an activation energy, E/sub (r)/ = 0.95 plus or minus 0.05 ev, which leads to a value of E/sub b/ of about the supersaturation. Some of the observations indicate that helical dislocation turns can degenerate into loops, possibly accounting for the high density of columns of loops observed in quenched aluminum alloys. (auth)

• Research Organization: California. Univ., Berkeley. Lawrence Radiation Lab.
• DOE Contract Number: W-7405-ENG-48
• NSA Number: NSA-18-002233
• OSTI ID: 4149921
• Report Number(s): UCRL-10879
• Country of Publication: United States
• Language: English

Related Subjects

ALUMINUM ALLOYS
ANNEALING
BINDING ENERGY
CONFIGURATION
DEFECTS
DISLOCATIONS
ELECTRON MICROSCOPY
FOILS
HEAT TREATMENTS
HEATING
MAGNESIUM ALLOYS
METALS, CERAMICS, AND OTHER MATERIALS
QUENCHING
TEMPERATURE
VACANCIES