KINKING AND THE FRACTURE OF IONIC SOLIDS

Abstract

A single crystal undergoing plastic bending develops constraints due to the gradient in lateral contraction across the beam. These constraints result in lateral stresses which may be relieved by the process of anticlastic kinking. Temperature affects the structure of kink boundaries and their subsequent role in initiating fracture. At high temperatures the resultant dislocations are ineffective barriers to slip and the crystals are ductile. At low temperatures the resultant dislocations provide strong barriers to slip and cracks nucleate at the kink boundary. At very low temperatures fracture occurs before the second set of glide dislocations have been activated to generate anticlastic kinks. Relaxation of the lateral stress results in a complex fracture. Compatible observations of the change in fracture behavior under bending over different temperature ranges have been made on a number of ionic solids. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1961
Accession Number
AD0261171

Entities

People

  • C.h. Li
  • R.j. Stokes
  • T.l. Johnston

Organizations

  • Honeywell International, Inc.

Tags

Communities of Interest

  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Boundaries
  • Crystals
  • Dislocations
  • High Temperature
  • Isotherms
  • Low Temperature
  • Single Crystals
  • Temperature Gradients

Readers

  • Materials Science and Engineering.
  • Structural Dynamics.