Accession Number : AD0600233


Title :   ACOUSTIC EMISSION UNDER APPLIED STRESS.


Descriptive Note : Rept. for 15 Apr 63-14 Apr 64,


Corporate Author : LESSELLS AND ASSOCIATES INC WALTHAM MASS


Personal Author(s) : Schofield,B H


Report Date : May 1964


Pagination or Media Count : 36


Abstract : Studies were made to assess the role of the surface and surface films in the generation of acoustic pulses, i.e., acoustic emission of metals. Experiments were conducted on single crystals of pure gold of varying crystallographic orientation. Specific crystallographic orientations were chosen to evaluate the effect of screw and edge dislocation mobility separately. Specimens were deformed in tension in ambient atmosphere. Results indicate that the surface and its condition play a minor role in the generation of the acoustic pulses; the phenomenon being related to the volumetric condition. Specific observations suggest the development of structural faults during deformation, reminiscent of elemental twins. Emission characteristics peculiar to gold are discussed for the several experiments. (See also AD-419 177). (Author)


Descriptors :   *METAL CRYSTALS , GOLD , ACOUSTIC PROPERTIES , ACOUSTIC PROPERTIES , SURFACES , THIN FILMS , OXIDES , CRYSTAL DEFECTS , LOADS(FORCES) , DEFORMATION , HEAT TREATMENT


Distribution Statement : APPROVED FOR PUBLIC RELEASE