ULTRASONIC ATTENUATION AND SOME RELATED BEHAVIORS IN IRRADIATED ALKALI HALIDE CRYSTALS

Journal Article · Fri Mar 01 04:00:00 EST 1963 · J. Phys. Soc. Japan

OSTI ID:4666860

Okada, T; Suita, T

Sodium chloride crystals subjected to gamma irradiation from zero to about 10/sup 7/ r in total dose at room temperature were examined during deformation by the following experimental techniques: observation of the yield point on the stress-strain relationships, observation of the ultrasonic attenuation changes as a function of the load, and observation of birefringence band. The yield stress of irradiated sodium chloride crystal in general increased with gamma dose for the following pretreated specimens: as annealed in air, after plastic deformation of about two per cent, about two per cent deformation and then annealed in air. rhe yield stress vs irradiation dose curve of the crystals annealed in air had a maximum at the total dose of about 1.5 x 10/ sup 5/ r and a minimum at about 10/sup 6/ r. The stress-strain relationships and the attenuation change vs stress when the specimen was under load were similar for the early stages of plastic flow in annealed crystal, namely, near the stress where macroscopic yielding occurred, appreciable increases in the damping were observed; with further deformation the damping saturates at a certain value. The higher the irradiation dose, the smaller these saturation values were found to be. For irradiated crystals attenuation decreased by a small amount just above the yield stress notwithstanding the onset of plastic deformation, and increased with increasing load. Birefringence due to dislocations in glide bands of sodium chloride crystals clearly showed the initiation of the plastic fiow in an unirradiated crystal as well as irradiated. A tentative model is proposed to explain the experimental results. (auth)

• Research Organization: Osaka Univ.
• NSA Number: NSA-17-035769
• OSTI ID: 4666860
• Journal Information: J. Phys. Soc. Japan, Journal Name: J. Phys. Soc. Japan Vol. Vol: 18: Suppl. I
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

AIR
ALKALI METALS
CHEMISTRY
CRYSTALS
GAMMA RADIATION
HALIDES
LOW TEMPERATURE
MECHANICAL PROPERTIES
RADIATION DOSES
RADIATION EFFECTS
SODIUM CHLORIDES
ULTRASONICS