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Type of Document	Engineer's Thesis
Author	Ahmed, Nazeer
URN	etd-12062002-155405
Persistent URL	http://resolver.caltech.edu/CaltechETD:etd-12062002-155405
Title	Work hardening during pyramidal slip in zinc
Degree	Engineer's Degree
Option	Engineering and Applied Science
Advisory Committee	Advisor Name Title Unknown Committee Member
Keywords	None
Date of Defense	1964-11-01
Availability	unrestricted
Abstract NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. The elastic stress field and energy associated with an infinite straight edge dislocation in a hexagonal crystal parallel to the line of intersection of the (0001) and the [...] planes with its Burger's Vector in the [...] plane and the [...] direction is determined taking into account the anisotropy of the crystal. The nature of the solution is found to depend on the relative numerical values of the five independent elastic constants. All possible solutions are investigated and the solution for an isotropic crystal determined as a limiting case. The interaction force between two edge dislocations of opposite sign gliding on consecutive glide planes is studied. Expressions for the total energy of such a dislocation dipole are developed. Numerical results are given at three temperatures,-77[degrees]C, 31[degrees]C and 139[degrees]C. These results are used to develop a quantitative theory of strain hardening in a single zinc crystal subjected to uniaxial tension or compression in the direction of its crystallographic axis. It is proposed that such strain hardening is produced by the dislocation dipoles that are formed on dislocations which are moving on any one of the six [...] pyramidal planes when they intersect similar dislocations which are moving on other planes of the same type. The density of such dislocation dipoles as a function of the uniaxial strain along the crystallographic axis is determined and possible future avenues of research that could utilize these results indicated.
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