Accession Number : AD0286090

Title :   RESEARCH AND DEVELOPMENT ON ADVANCED GRAPHITE MATERIALS. VOLUME II. APPLICATIONS OF ANISOTROPIC ELASTIC CONTINUUM THEORY TO DISLOCATIONS IN GRAPHITE

Corporate Author : NATIONAL CARBON CO INC CLEVELAND OHIO

Personal Author(s) : SPENCE,G.B.

Report Date : JUL 1962

Pagination or Media Count : 1

Abstract : Eshelby, Read, and Shockley's (E SHELBY, J.D. R EAD, Wit., and Shockley, W., Acta Meta. 1:251 (1953 00, theory of dislocations in an anisotropic elastic continuum was used to derive formulas not involving complex numbers for the stress components of straight dislocations in certain symmetry directions. From these the dependence of stacking fault energy, gamma F, on the orientation of the Burgers vector and on the width of exten ed dislocations and triple partial rbbons and the dependence of gamma F on the radium of curvature of extended nodes were calculated. The re ults are rigorous for hexagonal crystals and approximate for general directions in (111) planes of FCC crystals. The theory is applied to graphite and lose-packed metals. All three methods of determining gamma F or graphite yield results which are compatible with the vale 0.6 + or - 0.2 erg/sq cm. The rough estimate of error is based on uncertainties in the elastic constants and differences in experimental results. (Author)

Descriptors :   *GRAPHITE, *STRESSES, BIBLIOGRAPHIES, CRYSTALS, DEFORMATION, ELASTIC PROPERTIES, MATHEMATICAL ANALYSIS, SURFACES, THEORY

Distribution Statement : APPROVED FOR PUBLIC RELEASE