Accession Number:

AD0658874

Title:

DYNAMICAL BEHAVIOR OF DISLOCATIONS,

Descriptive Note:

Corporate Author:

ILLINOIS UNIV URBANA

Personal Author(s):

Report Date:

1967-09-01

Pagination or Media Count:

41.0

Abstract:

Direct and indirect measurements of dislocation mobilities are reviewed. It is pointed out that no single functional relation between dislocation velocity and stress exists. Four limiting cases are classified schematically a pure metals and salts b covalent crystals and impure others each at low and high stress levels. For cases a and b at low stress levels linear viscosity is observed. It is pointed out that a previous treatment of the viscous drag by Mason neglects the dominant role of glide plane sliding and a new treatment is presented. For case b at high stress levels low temperatures flow is stress-activated and a model based on quantum-tunneling is presented and shown to compare favorably with experiments. The behavior of heterogeneous crystals is discussed. A model proposed by Copley and Kear that predicts dynamic anisotropy is reviewed. Author

Subject Categories:

  • Crystallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE