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Type of Document	Dissertation
Author	Pope, David Peter
URN	etd-10042002-081427
Persistent URL	http://resolver.caltech.edu/CaltechETD:etd-10042002-081427
Title	The mobility of edge dislocations in the basal slip system of zinc
Degree	PhD
Option	Engineering and Applied Science
Advisory Committee	Advisor Name Title Unknown Committee Member
Keywords	None
Date of Defense	1967-01-06
Availability	unrestricted
Abstract NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. This thesis presents the results of measurements of the velocities of edge dislocations in the basal slip system of zinc as a function of applied shear stress. All tests were conducted at room temperature on 99.999 per cent purity zinc monocrystals. Dislocations were revealed by means of the Berg-Barrett x-ray technique. Stress pulses of microsecond duration were applied to the test specimens by means of a torsion testing machine. Applied resolved shear stresses ranged from 0 to 17.2 x 10[superscript 6] dynes/cm[superscript 2] and measured dislocation velocities ranged from 40 to 700 cm/sec. The results of this study indicate that the velocity of edge dislocations in the basal slip system of zinc is linearly proportional to the applied resolved shear stress. These results are analyzed in terms of the phonon drag theory. Agreement between this theory and the results reported in this thesis is quite good. Further work is suggested that will provide a more definitive test of the phonon drag theory for limiting dislocation motion in metallic crystals.
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