Studies of strain rate effects in the deformation of solids by means of stress pulses and ultrasonic methods. Part I. Progress report, September 1, 1984-March 31, 1985

Technical Report · Wed Jan 01 04:00:00 EST 1986

OSTI ID:5540844

Elbaum, C; Hikata, A

Strain rate sensitivity and deformation mechanism of LiF single crystals were studied at room temperature. Plastic deformations were induced by a split Hopkinson bar system. The range of strain rate covered is from 0.2 to 14 s/sup -1/. Both annealed and irradiated single crystals of <100> crystallographic orientations were tested. Ultrasonic longitudinal and shear waves were propagated in the sample concurrently with the stress pulses and their attenuation and velocity changes were analyzed. It was found that the glide motions of dislocations are controlled by thermally activated processes with an activation volume of 7.9 x 10/sup -21/ cm/sup 3/ for annealed samples and 2 x 10/sup -21/ cm/sup 3/ for irradiated samples. The activation energy for annealed sample was estimated to be 0.63 eV. The strain rate sensitivity was found to be 0.53 MPa for annealed samples and 2.13 MPa for irradiated samples. The mobile dislocation density at 1.4 x 10/sup -3/ shear strain was found to be 4 x 10/sup 7/ cm/cm/sup 3/.

• Research Organization: Brown Univ., Providence, RI (USA). Metals Research Lab.
• DOE Contract Number: FG02-84ER45165
• OSTI ID: 5540844
• Report Number(s): DOE/ER/45165-2; ON: DE86012208
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ALKALI METAL COMPOUNDS
ANNEALING
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CRYSTALS
DEFORMATION
DISLOCATIONS
ELECTROMAGNETIC RADIATION
FLUORIDES
FLUORINE COMPOUNDS
GAMMA RADIATION
HALIDES
HALOGEN COMPOUNDS
HEAT TREATMENTS
IONIZING RADIATIONS
LINE DEFECTS
LITHIUM COMPOUNDS
LITHIUM FLUORIDES
LITHIUM HALIDES
MONOCRYSTALS
PHYSICAL RADIATION EFFECTS
RADIATION EFFECTS
RADIATIONS
SOUND WAVES
STRAIN RATE
ULTRASONIC WAVES