A Caltech Library Service

Dynamic Shear Deformation in Zinc Crystals


King, Kenneth Robert (1962) Dynamic Shear Deformation in Zinc Crystals. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/J5Q8-5C31.


The initial stages of yielding in single crystals of zinc have been investigated at temperatures of -292°F (-180°C), -93°F (-70°C) and +75°F (24°C), by means of rapidly applied constant stress pulses to produce slip along the basal planes of these crystals.

The experimental results are interpreted in terms of a dislocation mechanism based upon the assumptions that the average velocity of dislocations remains constant during the period of constant applied stress and that the density of moving dislocations increases in linear proportion to the plastic strain. The experimental curves of plastic strain vs. time exhibit the form predicted by the assumed dislocation mechanism. The average dislocation velocity is found to be proportional to the 2.5 power of the excess of the applied stress over the static yield stress. The purity of the specimen and the test temperature are found to influence the average dislocation velocity only through their influence upon the static yield stress.

These results show that the behavior of basal slip dislocations in zinc is qualitatively the same as the behavior of slip dislocations in lithium fluoride and silicon-iron, as reported by Johnston and Gilman and by Stein and Low, respectively. Hence it is concluded that the concept of a lattice resistance to dislocation motion proposed by Gilman to explain the observed behavior of lithium fluoride and silicon-iron can be applied equally well to explain the observed behavior of zinc, and in fact that this is the only explanation consistent with the observed results.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Materials Science and Physics)
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Materials Science
Minor Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Wood, David Shotwell (advisor)
  • Clark, Donald S. (advisor)
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1962
Record Number:CaltechTHESIS:08012011-141442374
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:6562
Deposited By: Tony Diaz
Deposited On:19 Aug 2011 23:14
Last Modified:06 Jul 2022 17:38

Thesis Files

PDF - Final Version
See Usage Policy.


Repository Staff Only: item control page