Accession Number : AD0690201

Title :   STRESS FIELDS AND INTERACTION STRESSES OF DISLOCATIONS NEAR FREE SURFACES.

Descriptive Note : Technical rept.,

Corporate Author : VIRGINIA UNIV CHARLOTTESVILLE DEPT OF MATERIALS SCIENCE

Personal Author(s) : Cotter,K. H. , Jr. ; Wilsdorf,H. G. F.

Report Date : JUN 1969

Pagination or Media Count : 92

Abstract : The expressions for the stress fields of screw and edge dislocations near free surfaces in anisotropic cubic crystals are developed using analytic or variational methods. The screw dislocation had its axis along <110> and was oriented on a (111) plane either intersecting or parallel to the surface. In the case for an edge dislocation, the axis was aligned with a <112> direction. By using the stress fields for the dislocations oriented parallel to the surface, the stresses required for dislocations to pass one another are compared with those encountered in an infinite medium. It was concluded that in some cases it is more difficult for dislocations to pass each other when under the influence of the surface than in the bulk. The effects of anisotropy are compared with the isotropic approximation. Also, the behavior of dissociated dislocations near free surfaces is discussed with a numerical example given. (Author)

Descriptors :   (*DISLOCATIONS, STRESSES), ELASTIC PROPERTIES, SURFACES, ANISOTROPY, DEFLECTION, COMPUTER PROGRAMS, TENSOR ANALYSIS

Subject Categories : Crystallography
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE