Date of Final Oral Examination (Defense)

12-2011

Type of Culminating Activity

Thesis

Degree Title

Master of Science in Materials Science and Engineering

Department

Materials Science and Engineering

Major Advisor

Megan E. Frary, Ph.D.

Abstract

Dynamic recrystallization (DRX) is the recrystallization that occurs during high temperature deformation of metals and alloys. While DRX has been observed experimentally, the parameters that affect the microstructure are still being explored. For example, the effects of temperature, strain rate, and initial grain size have already been studied, yet the effect of initial special boundary fraction is still unknown. Special boundaries are high-angle, low-energy grain boundaries. It is believed that higher initial fractions of special boundaries will lead to a delay in the onset of recrystallization and a higher peak stress.

Experimentation has shown that triple junctions are preferred nucleation locations for DRX. This work will look at the different types of triple junctions (categorized based on the number of special boundaries at the junction) and determine the effect that special boundaries have on the probability of nucleation. It was supposed that triple junctions without special boundaries would be preferred nucleation sites due to higher grain boundary energy. This work showed that triple junctions sites, particularly triple junctions without special boundaries, were the preferred nucleation location.

Share

COinS