Accession Number : AD0750712

Title :   Dislocation Damping in Single Crystals of Controlled Substructure.

Descriptive Note : Final rept. 1 Sep 67-31 Aug 72,

Corporate Author : NOTRE DAME UNIV IND DEPT OF METALLURGICAL ENGINEERING AND MATERIALS SCIENCE

Personal Author(s) : Fiore,Nicholas F.

Report Date : 01 OCT 1972

Pagination or Media Count : 8

Abstract : Techniques have been developed for reproducibly growing Cu single crystals of controlled dislocation cell size and controlled random dislocation density. The ultrasonic pulse-echo attenuation of the crystals of various substructure has been measured from 2 to 100 MHz. The resonance bar damping of the crystals has been measured from 2 to 250 kHz. The damping and attenuation have been found to strong functions of substructure, and the 'vibrating membrane' modification of the Granato-Lucke theory of dislocation damping has been proposed to explain the relationship. (Author)

Descriptors :   (*COPPER, *SINGLE CRYSTALS), (*DISLOCATIONS, DAMPING), (*INTERNAL FRICTION, MEASUREMENT), CRYSTAL GROWTH, GAMMA RAYS, DAMAGE, RADIATION EFFECTS, CRYSTAL DEFECTS, ULTRASONIC RADIATION, ATTENUATION

Subject Categories : Metallurgy and Metallography
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE